# Letterhead > Letterhead is a newsletter platform for publishers: write and send email newsletters, curate content into them, > sell and place promotions, manage your audience, automate journeys, and report on what performs. This is its help > center, plus the developer documentation for the Letterhead API. Notes for coding agents: - The API is described in OpenAPI 3: https://docs.tryletterhead.com/openapi.yaml. Prefer it to guessing endpoint shapes. - Authenticate with a company API key sent as `Authorization: Bearer `. A company key can read and change the whole audience, so keep it on a server; never put it in browser or mobile code. - For TypeScript and JavaScript, use the official package `@tryletterhead/sdk` (npm). It has a typed method for every API operation and adds the API flag each request needs. - Companies on their own Letterhead tenant call `https://.api.tryletterhead.com` instead of the default API host. - Every article below is also available as Markdown by adding `.md` to its path. All of them in one file: https://docs.tryletterhead.com/llms-full.txt. ## Developer tools - [OpenAPI description](https://docs.tryletterhead.com/openapi.yaml): the full Letterhead API, one file - [API reference](https://docs.tryletterhead.com/api/reference/): every endpoint, browsable - [TypeScript SDK on npm](https://www.npmjs.com/package/@tryletterhead/sdk): `npm install @tryletterhead/sdk` - [TypeScript SDK source](https://github.com/wherebyus/letterhead-typescript): README, examples and changelog ## API - [Coming from Sailthru](https://docs.tryletterhead.com/api/coming-from-sailthru.md): If you pull reporting out of Sailthru's list, blast, and profile endpoints, this maps each call and field onto the Letterhead API — including the calls that collapse into one and the handful of fields with no equivalent. - [Curate content in bulk via API](https://docs.tryletterhead.com/api/curate-content-in-bulk-via-api.md): Use the API to create many curations in one request, each naming which of your newsletters it should appear on, with a batch size limit and a clear error when a request is too big. - [Ensuring Successful Newsletter Delivery during ESP Migration](https://docs.tryletterhead.com/api/successful-migration.md): New to Letterhead? Please read through this article to know what you can do now to smoothly transition your existing newsletter over to Letterhead. - [Generate & manage API keys](https://docs.tryletterhead.com/api/managing-api-keys.md): Generate API keys from Settings → API Keys to authenticate integrations like Zapier or WordPress. A key is company-level and reaches every newsletter in your account. Treat keys as secret and replace any that stop working. - [How can I use webhooks with Letterhead?](https://docs.tryletterhead.com/api/webhooks.md): Webhooks are automated messages sent from applications, whenever a specific event occurs, and can be used to trigger an event in another app. - [Retrieve newsletter audience overlap data via API](https://docs.tryletterhead.com/api/retrieve-newsletter-audience-overlap-data-via-api.md): Use the API to retrieve audience overlap data showing shared subscribers between newsletter pairs and analyze combined reach across multiple newsletters. - [Sending your own HTML: what's tracked and what's required](https://docs.tryletterhead.com/api/sending-your-own-html.md): Opens and clicks are tracked automatically when you send your own HTML via the API — with limits on which links qualify, you add your own unsubscribe link using the unsubscribe merge tag, and HTML that fails validation or a non-Letterhead channel can get a send rejected. - [Using the Letterhead API](https://docs.tryletterhead.com/api/using-the-letterhead-api.md): Authenticate to the Letterhead API with a company API key sent as a Bearer token, or use the official TypeScript package or command-line tool. Coding agents can read these docs as Markdown. Manage contacts, letters, curations, promotions, segments, and reporting. ## Get Started - [Channel Administrator Quick Start Guide](https://docs.tryletterhead.com/get-started/channel-administrator-quick-start-guide.md): As a Channel Administrator, you manage content and the audience for your assigned channels. This guide covers logging in, what you can and can't access, and how to get started with newsletters, automations, and audience tools. - [Company Admin Quick Start Guide](https://docs.tryletterhead.com/get-started/company-admin-quick-start-guide.md): Welcome As a Company Admin , you have the highest level of access across your organization. You’ll manage multiple organizations and monitor performance across dashboards. Here’s how to get started: A - [Content Contributor Quick Start Guide](https://docs.tryletterhead.com/get-started/content-contributor-quick-start-guide.md): Task-oriented quick start for content contributors: log in, learn what you can (and can't) access, build a newsletter with templates and content blocks, and schedule your first send. - [Letterhead Glossary](https://docs.tryletterhead.com/get-started/letterhead-glossary.md): Not sure what something means? This glossary breaks down common terms you'll see in the Help Center. - [Managing Your Channel Settings](https://docs.tryletterhead.com/get-started/account-settings-channel.md): App-verified guide to Channel Settings — General, Sending emails, and Pages always appear; Integrations and Forms depend on your ESP and account setup — including social links, sender details, audience policies, and archive options. - [Organization Administrator Quick Start Guide](https://docs.tryletterhead.com/get-started/organization-administrator-quick-start-guide.md): Task-oriented quick start for organization administrators: log in, configure sending, invite your team, import your audience, and get your first newsletter out. - [Setting Up Multi-Factor Authentication (MFA) in Letterhead](https://docs.tryletterhead.com/get-started/setting-up-multi-factor-authentication-mfa-in-letterhead.md): To enhance the security of your Letterhead account, we now require Multi-Factor Authentication (MFA). ## Emails - [AI Text block](https://docs.tryletterhead.com/newsletters/ai-text-block.md): Use AI to generate contextual text content — summaries, intros, blurbs, and more — directly inside your newsletter. - [Build a feedback survey in your newsletter](https://docs.tryletterhead.com/newsletters/feedback-survey.md): Drive engagement and get valued feedback using this simple strategy within your newsletter. - [Can I Edit a Published Newsletter?](https://docs.tryletterhead.com/newsletters/can-we-edit-published-newsletter.md): This article explains how to make changes to a published newsletter by creating a copy and hiding the original version. - [Create newsletters in Letterhead while sending through your own ESP](https://docs.tryletterhead.com/newsletters/esp-integration.md): Build newsletters in Letterhead and send through the ESP you already use. Iterable and Mailchimp step by step, searching many connections by name or newsletter, Iterable snippets and Message Type IDs, plus the limits of external sending. - [Create, Edit, Delete and Activate/Deactivate a Template](https://docs.tryletterhead.com/newsletters/create-edit-and-activate-deactivate-a-template.md): Create, edit, tag, clone, activate and delete Templates in Letterhead, including starting a template from a ready-made starter template or from a newsletter you already send. Templates are reusable layouts that keep every newsletter consistent. - [Custom CSS in emails](https://docs.tryletterhead.com/newsletters/custom-css-in-emails.md): The Email CSS editor in your channel's Settings → Sending emails applies custom CSS to your emails in place of Letterhead's defaults, for styling beyond the built-in design tools. - [Drag and Drop a section](https://docs.tryletterhead.com/newsletters/drag-and-drop-a-section.md): Learn how to move a section within your newsletter by using the simple click, drag, and drop feature. - [Edit newsletter details as a company administrator](https://docs.tryletterhead.com/newsletters/edit-newsletter-details-as-a-company-administrator.md): Company administrators can open and edit their newsletters' details (name, web address, description, logo, timezone and contact details) from the Groups or Channels page, without asking Letterhead staff. - [How can I add curated content to my newsletter?](https://docs.tryletterhead.com/newsletters/curation-block.md): Add the Curations block to pull library articles into a newsletter, style it (layout, side-by-side columns, text, images, spacing, call to action, custom fields), set story order, run a picked story in full, use it in templates, or match stories to reader interests. - [How can I include my social profile as part of my newsletter?](https://docs.tryletterhead.com/newsletters/social-profiles.md): Letterhead offers a convenient Profile block that can be included in your newsletter, allowing your audience members to easily click on and view your social media profiles. - [How can I use HTML in Letterhead?](https://docs.tryletterhead.com/newsletters/html.md): How to use the HTML block and write a template from your own HTML, the merge tags you can put in it — including the unsubscribe and view-in-browser link tags — and the HTML elements and attributes that are supported. - [How can my audience members easily share my newsletter?](https://docs.tryletterhead.com/newsletters/social-share.md): Letterhead provides a Share block that can be added to your newsletter edition for your audience members to share your content. - [How do I add a background image to my newsletter?](https://docs.tryletterhead.com/newsletters/newsletter-background-image.md): A background image sits behind the content of your email and shows up on most modern email clients. It's a great way to add brand personality, set a seasonal mood, or carry a campaign visual through your newsletter. - [How do I copy a newsletter into another channel?](https://docs.tryletterhead.com/newsletters/copy-a-newsletter-to-another-channel.md): Copy a newsletter from one channel into another with the Copy Newsletter tool. The copy arrives as a draft in the destination channel, ready to edit and send. - [How do I copy, delete, or turn a newsletter into a template?](https://docs.tryletterhead.com/newsletters/convert-newsletter-to-template.md): Learn how to duplicate, delete, or convert an existing newsletter into a reusable template to save time and streamline your workflow. - [How do I create and schedule a newsletter from a template?](https://docs.tryletterhead.com/newsletters/create-schedule-template.md): Learn how to build a new edition of your newsletter by using an activated template. - [How do I create and schedule a newsletter?](https://docs.tryletterhead.com/newsletters/scheduling-newsletter.md): Create an edition in the composer, preview it on desktop and mobile, see what's left before you can schedule, see what's driving its Email Weight, check how many people it reaches, and schedule it for your audience. - [How do I curate using a URL?](https://docs.tryletterhead.com/newsletters/url-block.md): This article provides the steps on how to add URL placeholder/expanded links to your newsletter to easily share articles, events, social posts, and more. - [How do I find editions by the date they published?](https://docs.tryletterhead.com/newsletters/filter-editions-by-published-date.md): Filter the Emails list by a range of publish dates, on its own or alongside the status and tag filters. The filtered view stays in the page address, so you can bookmark or share it. - [How do I personalize my newsletters to my audience members?](https://docs.tryletterhead.com/newsletters/personalization.md): Personalize newsletters with merge tags such as firstName: subject lines, default values, chips while you write and how to style them, invalid tags, plus picking a real reader field from your Braze workspace on a Braze-sending channel. - [How do I resend an edition to readers who didn't open it?](https://docs.tryletterhead.com/newsletters/resend-to-non-openers.md): Resend a published edition to the readers who didn't open it, with a new subject line. Letterhead reuses the original content and audience, and leaves out anyone who already opened it. - [How do I setup social cards in my newsletter?](https://docs.tryletterhead.com/newsletters/social-card-setup.md): Social cards are the link previews that appear when your newsletter is shared on social media or in chat apps. Here's where to set the image, title, and preview text on any letter — including reusing an image from your company gallery. - [How do I use the new design settings?](https://docs.tryletterhead.com/newsletters/design-composer-settings.md): A tour of the composer's design settings: newsletter-wide style defaults plus the styling options on every block, including blocks sitting side by side in a two-column section, and how to add or reposition blocks around one. - [How do I use the Paragraph AI Rewrite tool? ](https://docs.tryletterhead.com/newsletters/ai-rewrite.md): Often customers need to summarize or reformat text for a newsletter. The AI rewrite tool helps them do this in just a few clicks. - [How do I use the RSS block?](https://docs.tryletterhead.com/newsletters/curations-rss-block.md): Add an RSS feed as a curations source and pull its articles straight into your newsletter with the RSS block. - [How does Letterhead address unsafe links?](https://docs.tryletterhead.com/newsletters/unsafe-links.md): To enhance deliverability for our customers and ensure the safety of their audience, Letterhead diligently works to maintain compliance with security and email delivery standards throughout the entire newsletter flow. - [How does the Google Docs integration work?](https://docs.tryletterhead.com/newsletters/google-docs-integration.md): Build your newsletter in Google Docs and import it into the Letterhead composer — including whether consecutive paragraphs share a block or get one each, and whether the text keeps the doc's own fonts and colours. - [How Link Styling Works in Your Newsletter](https://docs.tryletterhead.com/newsletters/link-styling-in-your-newsletter.md): Link color and style come from three layers — your channel's brand kit, the newsletter's own link style, and formatting on one specific link — the most specific one winning. Covers why composer and delivered email can differ slightly. - [How to Add a YouTube Video to Your Newsletter](https://docs.tryletterhead.com/newsletters/how-to-add-a-youtube-video-to-your-newsletter.md): This article explains how to add a YouTube video to your newsletter using the YouTube block. You'll learn how to customize the thumbnail, link, and appearance, and how to import and style the video's title above or below the thumbnail. - [How to Add and Customize a Logo in Your Newsletter](https://docs.tryletterhead.com/newsletters/how-to-add-and-customize-a-logo-in-your-newsletter.md): Set up your channel logo and use the Logo block in the newsletter composer, and switch off the "Made with Letterhead" branding in your footer. - [How to Add and Customize Polls in Your Newsletter](https://docs.tryletterhead.com/newsletters/how-to-add-and-customize-polls-in-your-newsletter.md): How to create, customize, and track polls in Letterhead, set the logo size on the page readers see after voting, and turn the readers who chose an answer into an audience segment — whichever email provider sent the newsletter. - [How to Adjust Mobile Font Size and Padding in Letterhead](https://docs.tryletterhead.com/newsletters/how-to-adjust-mobile-font-size-and-padding-in-letterhead.md): Customize mobile-specific font size and padding so your newsletters are easier to read and better spaced on phones and tablets. - [How to change or add an image in a newsletter?](https://docs.tryletterhead.com/newsletters/change-image-in-newsletter.md): How to add or swap an image in a draft newsletter, and every option for customizing how it appears. - [How to customize your newsletter using Heading and Paragraph blocks.](https://docs.tryletterhead.com/newsletters/customize-heading-paragraph-blocks.md): Learn how to style and adjust Heading and Paragraph blocks to create a polished newsletter. - [How to Run A/B Tests on Email Subject Lines in Letterhead](https://docs.tryletterhead.com/newsletters/b-tests-on-email-subject-lines-in-letterhead.md): This article explains how to set up and run an A/B test on email subject lines in your newsletters. A/B testing helps you automatically send the best-performing subject line to most of your audience, boosting open rates and engagement. - [Images added to your company gallery are now automatically named](https://docs.tryletterhead.com/newsletters/images-added-to-your-company-gallery-are-now-automatically-n.md): Images added to the company gallery from curated stories or web addresses are automatically named after their source, making them easier to find and identify. - [Manage verified senders and choose who sends each newsletter](https://docs.tryletterhead.com/newsletters/manage-verified-senders-and-choose-who-sends-each-newsletter.md): Manage a single company-wide list of verified senders, assign a default sender per newsletter, and override the sender in the scheduling step's Sending settings for individual editions. - [Multi-user editing alert](https://docs.tryletterhead.com/newsletters/composer-takeover.md): What happens if someone tries to edit a newsletter at the same time? - [Newsletter Delivery and Engagement Metrics Report](https://docs.tryletterhead.com/newsletters/newsletter-delivery-and-engagement-metrics-report.md): Understand how your newsletters perform, now with subscriber-level open data. When a newsletter is published, Letterhead displays delivery and engagement metrics directly on the newsletter's page. - [One content block for your library, feeds, and links](https://docs.tryletterhead.com/newsletters/content-block-sources.md): Curation, RSS, and URL blocks are one content block with a From Library / From URL selector: pick a source, switch it after building — your styling and layout carry over, except Full content, which a link can't render — and choose which source fits the job. - [Paste Markdown and turn it into editable newsletter blocks](https://docs.tryletterhead.com/newsletters/paste-markdown-and-turn-it-into-editable-newsletter-blocks.md): Paste a Markdown document into the Markdown block in a newsletter or company template, choose whether consecutive paragraphs share a block or get one each, then select Load Markdown to convert it into editable blocks—headings, paragraphs, images, lists, links, and formatting. - [Pick recent editions for Brand Voice from a dropdown](https://docs.tryletterhead.com/newsletters/improved-dropdown-for-selecting-recent-editions-in-brand-voi.md): When you base a channel's Brand Voice on recent editions, you choose them from a dropdown that opens to a checkable list and collapses once you're done, instead of an always-open list. - [Private newsletters and Hide from archive](https://docs.tryletterhead.com/newsletters/private-newletters.md): Hide from archive keeps an edition off your public archive page while still sending it normally. Hidden and public newsletters differ only in archive visibility, and recipients of a private newsletter can still open their own copy with View in browser. - [Reuse images from your company image gallery](https://docs.tryletterhead.com/newsletters/company-image-gallery.md): Every image your team uploads while building newsletters is collected in one searchable gallery you can pick from in any channel. Images can be named after the story or website they came from, so you can find them by name. - [Saved Block](https://docs.tryletterhead.com/newsletters/saved-block-library.md): The Saved Block allows users to save individual blocks — including their settings — as reusable templates. Saved blocks can be reused across newsletters and newsletter templates, helping ensure consistency and reducing repetitive setup work. - [Show a Block to Only Some Readers](https://docs.tryletterhead.com/newsletters/show-a-block-on-desktop-or-mobile-only.md): A block's condition can limit it to desktop or mobile readers, or to readers in chosen audience segments, so different people see different things in one send. The preview step lets you check the edition as any segment would receive it. - [Smart Subjects AI-Powered Subject Lines & Preview Texts](https://docs.tryletterhead.com/newsletters/smart-subjects-ai-powered-subject-lines-preview-texts.md): Use AI to craft compelling email subject lines and preview texts that boost open rates and save time. - [What can I do to improve my email deliverability?](https://docs.tryletterhead.com/newsletters/email-delivery.md): Want to avoid going to spam? Read our suggestions below. - [What Do Letterhead Statuses Mean?](https://docs.tryletterhead.com/newsletters/what-do-letterhead-statuses-mean.md): Each status in the newsletter sending process serves a distinct purpose, guiding the sender through the stages of creation, scheduling, and delivery. - [What does the Accessibility check flag before you send?](https://docs.tryletterhead.com/newsletters/accessibility-check.md): The Accessibility row in Content Check flags images with no alt text, buttons with no readable label or no background, button and body text that's hard to read, headings that skip a level, and links like "click here". - [What does the Links check flag before you send?](https://docs.tryletterhead.com/newsletters/link-check.md): The Links row appears in Content Check when you preview and schedule. It flags links a reader can't follow — no destination, unusable addresses, text styled like a link that isn't one — and visits every destination to catch pages that are gone or sites that don't answer. - [What happened to the Evvnt block?](https://docs.tryletterhead.com/newsletters/what-is-the-evvnt-block.md): The Evvnt events block has been retired and no longer appears in the composer. Newsletters you've already sent are unchanged, and we're exploring a new way to bring Evvnt events back. - [What Is An Archive Page?](https://docs.tryletterhead.com/newsletters/what-is-an-archive-page.md): Each newsletter has its own Archive page for past editions and subscribing. If Letterhead hosts your newsletters at your own dedicated address, that address's front page lists every newsletter, grouped by brand, so a visitor can sign up for the ones they want. - [What is Bounce Risk, and how do I lower it?](https://docs.tryletterhead.com/newsletters/bounce-risk.md): Bounce Risk appears at the top of the Content Check section when you preview and schedule, above Email Weight. It flags wording, links, and layout that mailbox providers refuse for policy reasons, and quotes the exact text or web address behind each finding. - [Why Did My Email Go to Spam?](https://docs.tryletterhead.com/newsletters/why-did-my-email-go-to-spam.md): If your emails are landing in spam, there are a few common reasons why this might be happening. Email providers use a combination of user engagement, sender reputation, and content filtering to determine inbox placement. - [Why is my image not visible in my newsletter?](https://docs.tryletterhead.com/newsletters/why-is-my-image-not-visible-in-my-newsletter.md): Why an image may not appear in your newsletter, which file formats display properly in all email clients, and why an animated GIF at or above your account's size limit (1MB unless raised), or one you crop or edit, shows as a still image. - [Why is my newsletter stuck in "Sending" or "Processing"?](https://docs.tryletterhead.com/newsletters/newsletter-stuck-sending.md): You scheduled your letter, the send time arrived, and now the status shows Processing or Sending, instead of moving to Published. - [Why is the Preview & Schedule button greyed out?](https://docs.tryletterhead.com/newsletters/preview-schedule-button-disabled.md): You've finished writing a letter, you head to schedule it, and the Preview and schedule button at the top-right of the editor won't click. It's greyed out and there's no obvious reason why. - [Working in Emails](https://docs.tryletterhead.com/newsletters/newsletters-overview.md): V3 canonical page-guide for the Emails area — compose, design, template, schedule, send, track, and find an edition in the list. Capability-level, no screenshots. ## Curations - [Add Stripe products to newsletters as content blocks](https://docs.tryletterhead.com/dynamic-content/add-stripe-products-to-newsletters-as-content-blocks.md): Sync products from Stripe into your curation pool as content blocks, so you can add them to newsletters without copying details manually. - [Adding data feeds in Letterhead](https://docs.tryletterhead.com/dynamic-content/adding-data-feeds-in-letterhead.md): Register a JSON API as a data feed, map its fields to your curation fields, and let its items flow into your Curations library — deduplicated and refreshed automatically, like an RSS feed. - [Adding RSS feeds in Letterhead](https://docs.tryletterhead.com/dynamic-content/adding-rss-feeds-in-letterhead.md): Connect RSS feeds so dynamic content flows into your Curations library — covering advanced feed crawling, automatic tagging, duplicate detection, how long curations are kept (including keeping them forever), resetting a feed, and managing feeds from the RSS Feeds tab. - [Curate from anywhere with the Letterhead browser extension](https://docs.tryletterhead.com/dynamic-content/how-to-use-the-letterhead-browser-extension.md): Install the Letterhead Chrome extension, find your tenant prefix and sign in, save articles from any webpage into your Curations library, copy a promotion's HTML for another tool, and fix links the extension can't pull. - [Custom fields for curations](https://docs.tryletterhead.com/dynamic-content/custom-fields-for-curations.md): Attach your own structured metadata to curated items for organizing, filtering, and display in sent emails. - [Ensuring your images appear in the RSS block](https://docs.tryletterhead.com/dynamic-content/ensuring-your-images-appear-in-the-rss-composer-block.md): Letterhead reads images from media:content, media:thumbnail, or enclosure nodes — here's how to structure your feed so images come through. - [Managing your Curations library](https://docs.tryletterhead.com/dynamic-content/managing-your-curation-library.md): Find, filter, curate, edit, and tag the items in your Curations library, see when each item was published and when it was added, add an article by hand, choose which newsletters a company-wide curation appears in, and understand the automatic IAB categories Letterhead applies. - [Map WordPress custom fields to Letterhead](https://docs.tryletterhead.com/dynamic-content/map-wordpress-custom-fields-to-letterhead.md): Map WordPress custom fields, categories, tags, and built-in metadata to Letterhead custom fields so structured data flows into curated posts automatically. - [Personalize image links with feed data](https://docs.tryletterhead.com/dynamic-content/personalize-image-links-with-feed-data.md): Use feed expressions to set image link URLs, so each recipient's image links to a different destination based on their connected data. - [Preview a newsletter as a reader in a chosen audience segment](https://docs.tryletterhead.com/dynamic-content/preview-a-newsletter-as-a-reader-in-a-chosen-audience-segmen.md): Preview a newsletter, company template, or automation email as an audience segment or one specific contact would see it, with their tags, segments and merge tags applied. On newsletters you can also send yourself that version as a test. - [RSS feed errors and how to revalidate a feed](https://docs.tryletterhead.com/dynamic-content/revalidating-an-rss-feed-in-letterhead.md): What each RSS feed error means, why it happens, how to fix the root cause, and how to revalidate an invalid feed so Letterhead starts checking it again. - [Stop a curation block repeating the same link](https://docs.tryletterhead.com/dynamic-content/stop-a-curation-block-repeating-the-same-link.md): A fully set-up curation block links its image, its headline, and its read-more prompt to the same story. Switch off the image or headline link so readers get one obvious place to click. - [Working in Curations](https://docs.tryletterhead.com/dynamic-content/curations-overview.md): V3 canonical page-guide for the Curations area — capability-level, no screenshots. ## Promotions - [How to Add External Promotions Using the HTML Block](https://docs.tryletterhead.com/promotions/how-to-add-external-promotions-using-the-html-block.md): If you manage promotions through an external platform, include them in your Letterhead newsletters using the HTML block — paste the code, swap in Letterhead merge tags, and click Relax HTML Validation. - [How to Set Up Promotions in Letterhead](https://docs.tryletterhead.com/promotions/how-to-set-up-promotions-in-letterhead.md): Set up campaigns, add promotions, and place them in newsletters to monetize your channels. - [How to Update the Character Limit on a Promotion Type](https://docs.tryletterhead.com/promotions/how-to-change-the-character-limit-on-a-promotion-type-1.md): Adjust character limits on promotion templates — legacy organization-level promotions only. Company-level promotions have no equivalent setting today. - [How to Use Auto Inject for Promotions in Newsletters](https://docs.tryletterhead.com/promotions/how-to-use-auto-inject-for-promotions-in-newsletters.md): Auto Inject places promotions in predefined newsletter spots automatically, including company promotions that inject into every send, with no manual drag-and-drop. - [How to Use Company-Level Promotions](https://docs.tryletterhead.com/promotions/how-to-use-company-level-promotions.md): Create, manage, and use Company-Level Promotions to run promotions across multiple organizations and channels from one place. - [How to use HTML Promotions](https://docs.tryletterhead.com/promotions/how-to-use-html-promotions.md): HTML Promotions let you add, schedule, and manage custom HTML creatives as a dedicated promotion type. Google Ad Manager ads need Ad Manager 360 newsletter tags — the free version only makes JavaScript tags, which don't run in email. - [Promotion lifecycle: clone, auto-expire, set inactive](https://docs.tryletterhead.com/promotions/promotion-lifecycle.md): Manage the promotion lifecycle by cloning existing promotions, marking them inactive, setting automatic expiration by date, or ending a running promotion early. - [Promotions analytics](https://docs.tryletterhead.com/promotions/promotions-insights.md): Track promotion performance across your account with company-level analytics showing impressions, clicks, CTR, your best-performing promotions and sends, and the Promotion Clicks card in your company analytics overview. - [Using the 2-Column Promotion Block](https://docs.tryletterhead.com/promotions/using-the-2-column-promotion-block.md): The 2-column Promotion block displays two promotions side by side, keeping multiple promotions in one section compact and visually balanced. - [What Are Letterhead's Default Promotion Types?](https://docs.tryletterhead.com/promotions/what-are-promotion-types.md): Letterhead ships four default promotion types — Text, Image with text, and Banner use required fields promoters complete; HTML lets you paste your own custom markup instead. - [Working in Promotions](https://docs.tryletterhead.com/promotions/promotions-overview.md): Page-guide for the Promotions area — tabs, capabilities, and where things live. ## Transactional Email - [Send transactional email](https://docs.tryletterhead.com/transactional-email/send-transactional-email.md): Send transactional emails (receipts, confirmations, notifications) separately from your newsletter campaigns, check whether each one was sent, refused, delivered or bounced, and track performance by tag. - [View performance metrics for transactional emails](https://docs.tryletterhead.com/transactional-email/view-performance-metrics-for-transactional-emails.md): See sends, open/click/bounce/spam rates and refused counts for your transactional emails, each send's status and reason, or ask the AI assistant for metrics grouped by tag. ## Audience - [Audience Profile Activity Log](https://docs.tryletterhead.com/audience/audience-profile-activity-log.md): View each contact's engagement — newsletter opens, link clicks, promotion clicks, bounces, Stripe purchases, and IP activity — from their profile page. - [Can I Subscribe the Same Audience to a New Newsletter?](https://docs.tryletterhead.com/audience/can-i-subscribe-the-same-audience-to-a-new-newsletter.md): What the law allows when emailing existing subscribers about a new publication — and the best practice we recommend. - [Custom fields for contacts](https://docs.tryletterhead.com/audience/custom-fields-for-contacts.md): Create custom fields on your contacts (like city or subscription plan) for advanced segmentation and personalized email content, and see what happens when a value looks like sensitive information such as a card number. - [Deleting audience members and their contact details](https://docs.tryletterhead.com/audience/why-deleting-audience-members-is-not-supported.md): Audience members can't be deleted, for CAN-SPAM compliance. Classic per-channel audiences can replace their whole list with a Delete & Overwrite import; on company-wide Contacts, request a targeted deletion or a legal/compliance removal (e.g. GDPR) through support. - [Do I need to warm up and verify emails prior to my first send with Letterhead?](https://docs.tryletterhead.com/audience/sending-email-addresses.md): Warming up an IP prior to sending with Letterhead is not required — plus optional strategies if your list may contain many dead addresses, and what the paid, opt-in Recipient Validation feature does and doesn't cover. - [Export your audience](https://docs.tryletterhead.com/audience/export-your-audience.md): Export your subscriber list from the Audience view, whole or narrowed to a custom segment, and see roughly how long a large export takes and, for API or Penpal exports, how far along it is. - [How can I add a subscriber to my account?](https://docs.tryletterhead.com/audience/add-subscriber.md): Add single or multiple subscribers to your Audience list using the method that suits your workflow. - [How Do I Import Subscribers?](https://docs.tryletterhead.com/audience/csv-upload.md): Format your CSV, choose an import type, map your columns to Letterhead fields, and validate rows with the guided importer. On the company-wide Contacts importer, keep columns that match no field as new custom fields and the same import fills them. - [How do tags and segments work?](https://docs.tryletterhead.com/audience/user-tags-and-segments.md): Organize contacts with tags — individually, in bulk, or by who opened or clicked a newsletter — build segments from tags, profile fields, and engagement (including rolling time windows), edit or delete them, copy any segment's ID, and target newsletters to specific groups. - [How to View or Edit an Audience Member](https://docs.tryletterhead.com/audience/view-edit-audience-member.md): Search and filter your contacts list, open a subscriber's profile, and update their status, tags, and profile details. - [Is it possible for administrators to re-subscribe audience members?](https://docs.tryletterhead.com/audience/as-an-administrator-am-i-able-to-re-subscribe-audience-members.md): Organization and Channel Administrators re-subscribe audience members from the Audience page by setting their status to Subscribed. With double opt-in on (the default), that lands them in Pending Confirmation until they confirm by email instead of resubscribing right away. - [List Optimization](https://docs.tryletterhead.com/audience/letterhead-list-cleanup.md): List Optimization (list cleanup) keeps your email list healthy by identifying and managing inactive contacts to boost deliverability and engagement. - [Manage all your signup pages and subscribe forms](https://docs.tryletterhead.com/audience/manage-all-your-signup-pages-and-subscribe-forms.md): See and edit all your signup pages and subscribe forms — main signup page, group pages, newsletter pages, and embed forms — from one list with live previews. A newsletter's page and its embedded form can also let readers sign up for your text messages. - [Managing Audience Members in Pending Confirmation Status](https://docs.tryletterhead.com/audience/confirmation-emails.md): What you can do when someone hasn't confirmed their subscription yet, including support options and a careful re-opt-in workaround. - [Personalization Tags](https://docs.tryletterhead.com/audience/personalization-tags.md): A guide to personalization tags for email newsletters, covering basic and advanced fields, hashed email address tags, default values, publication-date formats, and how tag support differs on the newer company-wide Contacts experience. - [Save signup form responses to contact records](https://docs.tryletterhead.com/audience/save-signup-form-responses-to-contact-records.md): When readers complete extra fields in your signup form, their responses save directly to their contact record for filtering and segmentation. - [See your audience import history and retry a failed import](https://docs.tryletterhead.com/audience/audience-import-history-and-retrying-a-failed-import.md): Your company's Contacts page keeps a history of every audience import — status, counts, and who started it — with a way to see which rows failed, retry an import that stopped partway, and finish or cancel one waiting on your choice of columns. - [Segment readers near a location](https://docs.tryletterhead.com/audience/segment-readers-near-a-location.md): Build a segment around where your readers are: search for a city or town, set a distance in miles, and see how many readers fall inside that radius before you save. - [Send readers to your newsletter directory page](https://docs.tryletterhead.com/audience/send-readers-to-your-newsletter-directory-page.md): If you have a dedicated address, its front page now lists every newsletter you publish, grouped by brand, for readers to browse and subscribe. - [Smart Engagement-Based Segments](https://docs.tryletterhead.com/audience/engagement-based-segments.md): Smart Engagement-Based Segments automatically group subscribers by how recently and often they open or click, updating automatically so you can target the right audience. - [Understanding bounces & Letterhead's bounce handling](https://docs.tryletterhead.com/audience/understanding-bounces.md): Soft bounces, hard bounces, how Letterhead filters bounced addresses, and how to deal with bounces on your list. - [View newsletter reputation scores in List Health and Portfolio Health](https://docs.tryletterhead.com/audience/view-newsletter-reputation-scores-in-list-health-and-portfol.md): See a color-coded reputation score (0–100) for each newsletter in your List Health and Portfolio Health tables — an instant read on deliverability standing. - [View reader interests on subscriber profiles](https://docs.tryletterhead.com/audience/view-reader-interests-on-subscriber-profiles.md): Letterhead shows inferred reader interests on individual subscriber profiles based on engagement history, and you can build segments around these interests. - [View suppression status and reasons on a contact profile](https://docs.tryletterhead.com/audience/view-suppression-status-and-reasons-on-a-contact-profile.md): Contact profiles show a dedicated Suppressions section listing every newsletter the contact can't receive, the reason why, and when it happened, including bounce details. - [What are audience profile fields in Letterhead?](https://docs.tryletterhead.com/audience/how-profile-fields-work.md): Audience profile fields let you store detailed information about your audience members for segmentation and personalization. - [What Happens When Someone Unsubscribes From Your Newsletter?](https://docs.tryletterhead.com/audience/what-happens-when-someone-unsubscribes-from-your-newsletter.md): Unsubscribe requests are processed immediately. Readers can leave one newsletter or everything you send in one step from the preferences page — here's how it works and how to troubleshoot it. - [What is the Organization Audience page?](https://docs.tryletterhead.com/audience/organization-audience.md): Organization administrators can view audience members across all their channels, see which channels each member belongs to, and filter by search, channel, or status. - [Working in Audience](https://docs.tryletterhead.com/audience/audience-overview.md): V3 canonical page-guide for the Audience area — capability-level, no screenshots. ## Goals - [Goals Overview](https://docs.tryletterhead.com/goals/using-goals.md): Goals let you set measurable performance targets — at company, brand, or channel level — and track progress on the Goals dashboard, plus what shows on the company Home page while a send is happening live. ## Automations - [Add tag assignment steps to any automation](https://docs.tryletterhead.com/automations/add-tag-assignment-steps-to-any-automation.md): Add a tag-assignment step to any automation, regardless of its trigger, and see how many subscribers it has tagged while the automation runs. - [Automation email preferences](https://docs.tryletterhead.com/automations/automation-email-preferences.md): Each automation series has its own sending settings, separate from your regular newsletter settings. Options vary by series — check the settings panel of your automation. - [Automation triggers overview](https://docs.tryletterhead.com/automations/automation-triggers-overview.md): Letterhead automations are triggered by new subscribers, subscriber status changes, tags, curation items, email opens and link clicks (narrowable to specific emails and links, including did-not-open/did-not-click), date & time, and subscriber inactivity. - [Branch a simple series automation](https://docs.tryletterhead.com/automations/branch-a-simple-series-automation.md): Branch a Simple Series automation by engagement (opens or clicks, optionally narrowed to specific links) or by audience attributes, and nest branches at any depth for multi-level logic. - [Build a re-engagement series](https://docs.tryletterhead.com/automations/build-a-reengagement-series.md): A re-engagement series targets subscribers who've gone quiet, using the Subscriber inactivity trigger (your Ghost segment): set the trigger, design message steps, and activate. - [Company-Level Automations Errors Table](https://docs.tryletterhead.com/automations/automations-errors-table.md): Find out when an automation fails and why: filter your company's automations by Error status, search by title, template, channel or ID, see the exact time of each send and the segment it targets, and keep your filters as a link you can share. - [Create an Automation for Welcome letters & Recurring newsletters](https://docs.tryletterhead.com/automations/automations-1.md): Letterhead offers two ready-made automation options — Welcome Email and Recurring Email — for fully hands-off sending. - [How to Send a Test Email from Your Automation](https://docs.tryletterhead.com/automations/preview-automated-emails.md): Send yourself and others test emails from an automation — recurring or not — to check content, dynamic blocks, and formatting before it goes live. - [Journey-specific unsubscribe links in automation emails](https://docs.tryletterhead.com/automations/journey-specific-unsubscribe-links-in-automation-emails.md): Automation emails include a journey-specific unsubscribe link, so readers can opt out of one automation series while staying subscribed to your newsletter. - [Manage an automation series](https://docs.tryletterhead.com/automations/manage-an-automation-series.md): Manage active automation series: pause/reactivate, update message content, restart for new subscribers, delete, and review performance and errors. - [Monitor a running automation](https://docs.tryletterhead.com/automations/view-automation-performance-metrics-on-the-workflow-canvas.md): One place to monitor a running automation: journey and enrollment metrics, per-step and per-branch subscriber counts, per-step email performance, and read-only configuration. - [Split an automation by subscriber attributes](https://docs.tryletterhead.com/automations/split-an-automation-by-subscriber-attributes.md): Branch an automation based on subscriber profile details or tags, using the same criteria as audience segments. - [Working in Automations](https://docs.tryletterhead.com/automations/automations-overview.md): V3 canonical page-guide for the Automations area — capability-level, no screenshots. ## AI Agents - [AI Agents overview](https://docs.tryletterhead.com/ai-agents/ai-agents-overview.md): Letterhead provides AI agents to help create, review, and analyze newsletters. Each agent runs automatically, on a schedule, or on demand, depending on its type — review its findings and suggestions afterward. - [Analyze agent](https://docs.tryletterhead.com/ai-agents/analyze-agent.md): The Analyze agent reviews your performance data to surface trends, insights, and actionable recommendations for improving your newsletters. - [Ask the assistant why a link looks different in the inbox](https://docs.tryletterhead.com/ai-agents/ask-the-assistant-why-a-link-looks-different-in-the-inbox.md): Penpal can now explain why a link's appearance differs in the delivered newsletter from how it looked while writing—checking both newsletter-level styling and inline formatting you applied to that text. - [Create & manage agents](https://docs.tryletterhead.com/ai-agents/create-and-manage-agents.md): Build custom agents to automate your newsletter workflow. Choose a template or create from scratch and configure the agent's prompt — how it runs (automatic, scheduled, or on demand) depends on its type. - [Email Content Check agent](https://docs.tryletterhead.com/ai-agents/email-content-check-agent.md): The Email Content Check agent automatically flags content issues (broken links, missing alt text, etc.) in your newsletters. It runs automatically when you set an email to preview before scheduling, catching problems early. - [Get notified when your Analyze agent finishes reviewing a newsletter](https://docs.tryletterhead.com/ai-agents/get-notified-when-your-analyze-agent-finishes-reviewing-a-ne.md): Receive in-app notifications and email digests when your Analyze agent finishes reviewing a newsletter, so you don't have to wait and watch for results. - [Manage your promotions with the AI assistant](https://docs.tryletterhead.com/ai-agents/manage-promotions-with-the-ai-assistant.md): Use Letterhead's assistant — in the app or through a connected AI client — to review, edit, reschedule, pause, or remove your promotions in plain language. - [Review agent runs & judgments](https://docs.tryletterhead.com/ai-agents/review-agent-runs.md): The Agent Feed shows past runs and their outputs. Review the findings (read-only) to act on their recommendations. - [Set goals, schedule reports, and manage automations with the AI assistant](https://docs.tryletterhead.com/ai-agents/set-goals-schedule-reports-and-manage-automations-with-the-a.md): When connected via an AI client like Claude Desktop, Letterhead's assistant can set goals, schedule recurring reports, check automation status, and pull company-wide performance data. - [Tag, segment, and update groups of contacts with the AI assistant](https://docs.tryletterhead.com/ai-agents/tag-segment-and-update-contacts-in-bulk-with-the-assistant.md): Ask Penpal to look up a contact, tag a group, create a segment, plan a multi-day warm-up, edit a field, change newsletter subscriptions, or delete contacts. It shows how many contacts it would touch and waits for your confirmation first. - [Working with Penpal, Letterhead's AI assistant](https://docs.tryletterhead.com/ai-agents/edit-your-newsletter-in-conversation-with-the-assistant.md): The general guide to Penpal, the assistant panel on every page of Letterhead: opening it, answering a yes-or-no question with one click, chat history, human handoff, what it does with a newsletter, and what it will and won't help with. ## Reports - [Export reports, or schedule them by email](https://docs.tryletterhead.com/reports/how-to-export-reports-in-letterhead.md): Pick a report type, choose a date range from the past six months, and add up to five email recipients for a one-off export — or set the same report to arrive automatically daily, weekly, or monthly. Reports are emailed from reports@admin.letterhead.email. - [Letterhead Reporting](https://docs.tryletterhead.com/reports/letterhead-reporting.md): How Letterhead's audience growth metrics, subscriber growth charts, and click, engagement, and audience growth reports fit together — plus key metric definitions. - [Reading the click heat map](https://docs.tryletterhead.com/reports/click-heat-map.md): The click heat map overlays a sent letter with color by total clicks per link, so you can see which stories, buttons, and ads earned attention. Includes the heatmap toggle on a published newsletter's preview. - [Reports Overview: Metrics, Columns, and Use Cases](https://docs.tryletterhead.com/reports/reports-overview-metrics-columns-and-use-cases.md): Column-by-column reference for Clicks, Newsletter Engagement, and Audience Growth reports, with tips for using each. - [Understanding hard bounces and soft bounces in your reports](https://docs.tryletterhead.com/reports/understanding-hard-bounces-and-soft-bounces-in-your-reports.md): Newsletter reporting shows hard bounces (permanent failures) and soft bounces (temporary issues) as separate metrics alongside the total bounce count. - [Working in Reports](https://docs.tryletterhead.com/reports/reports-overview.md): V3 canonical page-guide for the Reports area — capability-level, no screenshots. ## Dashboards - [Audience metrics dashboard](https://docs.tryletterhead.com/dashboards/audience-metrics-dashboard.md): Monitor audience health with metrics on total subscribers, new subscribers, unsubscribes, and net growth trends to measure newsletter performance. - [Clicks dashboard](https://docs.tryletterhead.com/dashboards/clicks-dashboard.md): Track which links in your newsletters received the most clicks on the Content tab, and compare each topic's share of the links you publish against its share of clicks to see what readers want more or less of. - [Compare reader groups across your newsletters](https://docs.tryletterhead.com/dashboards/compare-reader-groups-across-your-newsletters.md): Select several reader groups — Loyalists, New & Engaged, Casual, Fading, Ghosts — on the Dashboard's Audience tab and see each one's share of every newsletter's list in a single table. - [Track engagement over time for any audience segment](https://docs.tryletterhead.com/dashboards/track-engagement-over-time-for-any-audience-segment.md): View engagement trends over time for any saved segment — or your whole audience — with day-by-day open rate, clickthrough rate, click-to-open rate, and bounce rate plotted against your whole-audience baseline, filterable by newsletter and exportable as CSV. - [Understanding the Dashboard: Overview, Emails, Audience & Content](https://docs.tryletterhead.com/dashboards/understanding-the-audience-engagement-and-delivery-dashboards.md): The Dashboard under Analytics has four tabs — Overview, Emails, Audience, and Content — covering engagement KPIs, human-vs-bot engagement quality, audience health, and click behavior, with channel and date filters, CSV/PDF export, and a test mode that shows sample data. ## Settings - [How Do I Add a Team Member to Letterhead?](https://docs.tryletterhead.com/settings/add-team-member.md): Invite team members at the organization level, choose one of three roles, and remove access when needed. Support staff never appear in your team list. - [How do I set up my custom sending domain?](https://docs.tryletterhead.com/settings/sending-domain-configuration.md): Add a sending subdomain, publish the CNAME, DKIM, SPF, and DMARC records with your DNS provider, verify the domain in Letterhead, and warm up a new domain gradually. - [How do you opt-out of double opt-ins?](https://docs.tryletterhead.com/settings/opt-in.md): Double opt-in requires new subscribers to confirm their sign-up. It's set per channel, under that channel's Settings > Sending emails > Audience Policies — there's no organization-wide default. - [How to Reset Your Password](https://docs.tryletterhead.com/settings/how-to-reset-your-password.md): Use Forgot Password on the login screen, follow the emailed reset link (expires in 30 minutes), and set a new password. - [How to Use Company-Level Newsletter Templates in Letterhead](https://docs.tryletterhead.com/settings/company-level-templates.md): Create, preview, and activate company-level templates that all channels can use, from a Preview and activate panel laid out like the scheduling panel. Channel users can clone a shared template to customize their own copy. - [Letterhead's Recipient Validation](https://docs.tryletterhead.com/settings/letterhead-recipient-validation.md): Recipient Validation checks new email addresses from imports, embed forms, and archive signups, marking invalid ones as cleaned. A paid premium feature enabled through your Account Manager. - [Manage company settings in a shared Letterhead account](https://docs.tryletterhead.com/settings/manage-company-settings-in-a-shared-letterhead-account.md): Companies sharing a Letterhead account can manage all settings — team roles, integrations, email providers, verified domains, and AI assistant details — with changes scoped to their own company. - [Manage sending domains for your company email connection](https://docs.tryletterhead.com/settings/manage-sending-domains-for-your-company-email-connection.md): Add, verify, re-verify, and remove sending domains directly within your company-level Letterhead email connection settings. - [Managing Brand Kits from a Central Company-Level Screen](https://docs.tryletterhead.com/settings/managing-brand-kits.md): Manage your company's brand kits from one screen — create, duplicate, delete, or have Penpal make one for each newsletter; configure Styles (or fill them in from a newsletter you send), Brand Voice, and Social Profiles; and apply a kit to an existing newsletter or template. - [Managing Company-Wide Promotions](https://docs.tryletterhead.com/settings/managing-company-wide.md): Company admins can create promotion campaigns, assign them to channels and zones, schedule runs, auto-inject them into sends, and export performance data. - [Managing your notifications](https://docs.tryletterhead.com/settings/managing-your-notifications.md): Manage notifications from a dedicated page, choosing which events reach you and how (in-app, email, or both), and see what is new in Letterhead from the bell and a What's new page. - [What is BIMI and How to Set It Up](https://docs.tryletterhead.com/settings/what-is-bimi-and-how-to-set-it-up.md): BIMI prerequisites (DMARC at enforcement, SVG Tiny-PS logo, VMC/CMC certificate), the DNS record to publish, and troubleshooting when the logo doesn't appear. - [Working in Settings](https://docs.tryletterhead.com/settings/settings-overview.md): V3 canonical page-guide for the Settings area — capability-level, no screenshots. ## Integrations - [Company-Level CRM Audience Sync Integration (HubSpot & Mailchimp)](https://docs.tryletterhead.com/integrations/company-level-crm-audience-sync-integration.md): Pull contacts from HubSpot or Mailchimp into Letterhead at the company level — a one-way sync into Letterhead, not a live, bi-directional connection. - [Connect AI tools to Letterhead (MCP)](https://docs.tryletterhead.com/integrations/connect-ai-tools-mcp.md): Letterhead exposes a Model Context Protocol (MCP) server so AI tools can query channels, letters, and performance metrics. Add Letterhead as a custom connector in your AI client and sign in with OAuth. - [Connect Iterable data feeds to your channel](https://docs.tryletterhead.com/integrations/connect-iterable-data-feeds-to-your-channel.md): Configure Iterable data feeds at the channel level so dynamic content automatically appears in every newsletter without reconnecting the feed each time. - [Connect Letterhead to Google Postmaster](https://docs.tryletterhead.com/integrations/google-postmaster.md): Connect Google Postmaster with a read-only sign-in to see Gmail's view of your sending — spam rate, domain reputation, SPF/DKIM/DMARC, and delivery errors — per sending domain, without opening Google's dashboard. - [Connect Letterhead to Shopify](https://docs.tryletterhead.com/integrations/shopify.md): Connect your Shopify store to see purchases on contact profiles, add purchasers to your audience, and feature the things you sell in newsletters as content blocks. - [Connect Letterhead to Stripe](https://docs.tryletterhead.com/integrations/stripe.md): Connect Stripe with a read-only API key to see purchase activity on contact profiles, sync customers into your audience, and feature Stripe products in newsletters as content blocks. - [Connect OptinMonster to capture signup leads](https://docs.tryletterhead.com/integrations/connect-optinmonster-to-capture-signup-leads.md): Connect OptinMonster to automatically route signup leads from your OptinMonster campaigns into Letterhead channels, using a webhook URL and signing secret you add on OptinMonster's side. - [How can I set up the Slack integration?](https://docs.tryletterhead.com/integrations/slack-integration.md): Connect your Slack workspace to Letterhead and get notifications about your newsletters directly in a Slack channel. - [How to Use the Letterhead WordPress Plugin](https://docs.tryletterhead.com/integrations/connecting-your-wordpress-site-with-letterhead.md): How to install, connect, and use the Letterhead WordPress plugin so your WordPress posts, tags, and custom fields flow into the Letterhead Curations library. - [Iterable Message Type ID validation now happens when you open settings](https://docs.tryletterhead.com/integrations/iterable-message-type-id-validation-now-happens-when-you-ope.md): Iterable Message Type IDs are validated each time you open newsletter settings. Invalid IDs show a warning immediately, and temporary Iterable outages no longer prevent saving. - [Letterhead + Zapier](https://docs.tryletterhead.com/integrations/zapier.md): Use Zapier with a company-level API key to manage your whole company audience — add or update contacts, manage tags, and push articles into Curations — no code required. - [Personalize images with Iterable data feeds](https://docs.tryletterhead.com/integrations/personalize-images-with-iterable-data-feeds.md): If you send through Iterable, you can use data-feed expressions in image blocks to personalize images per recipient at send time. - [Send a daily data export to your Amazon S3 bucket](https://docs.tryletterhead.com/integrations/send-a-daily-data-export-to-amazon-s3.md): Connect an Amazon S3 bucket you own and receive a daily JSON export of your contacts, the newsletters sent the day before, and sent, opened, clicked, bounced and unsubscribed events, with a history of each day's run you can re-run. - [Send newsletters through Braze](https://docs.tryletterhead.com/integrations/send-newsletters-through-braze.md): You can now connect Braze as your sending provider to publish newsletters through it and use Braze's personalization fields and conditional content blocks. - [Working in Integrations](https://docs.tryletterhead.com/integrations/integrations-overview.md): What each Letterhead integration does: sending through an ESP, CRM audience sync (including Salesforce), Stripe, Shopify, OptinMonster, CitySpark, Zapier, Slack, WordPress and AI tools — and, for anything not built in, whether to reach for Zapier, the API, or webhooks. ## Release Notes - [What's new — week of Aug 10, 2026](https://docs.tryletterhead.com/release-notes/2026-08-10-whats-new.md): 5 updates shipped during the week of Aug 10, 2026. - [What's new — week of Aug 17, 2026](https://docs.tryletterhead.com/release-notes/2026-08-17-whats-new.md): 5 updates shipped during the week of Aug 17, 2026. - [What's new — week of Aug 24, 2026](https://docs.tryletterhead.com/release-notes/2026-08-24-whats-new.md): 11 updates shipped during the week of Aug 24, 2026. - [What's new — week of Aug 3, 2026](https://docs.tryletterhead.com/release-notes/2026-08-03-whats-new.md): 6 updates shipped during the week of Aug 3, 2026. - [What's new — week of Aug 31, 2026](https://docs.tryletterhead.com/release-notes/2026-08-31-whats-new.md): 2 updates shipped during the week of Aug 31, 2026. - [What's new — week of Jul 13, 2026](https://docs.tryletterhead.com/release-notes/2026-07-13-whats-new.md): 6 updates shipped during the week of Jul 13, 2026. - [What's new — week of Jul 20, 2026](https://docs.tryletterhead.com/release-notes/2026-07-20-whats-new.md): 13 updates shipped during the week of Jul 20, 2026. - [What's new — week of Jul 27, 2026](https://docs.tryletterhead.com/release-notes/2026-07-27-whats-new.md): 8 updates shipped during the week of Jul 27, 2026. - [What's new — week of Jul 6, 2026](https://docs.tryletterhead.com/release-notes/2026-07-06-whats-new.md): 4 updates shipped during the week of Jul 6, 2026. - [What's new — week of Jun 29, 2026](https://docs.tryletterhead.com/release-notes/2026-06-29-whats-new.md): 24 updates shipped during the week of Jun 29, 2026. - [What's new — week of June 22, 2026](https://docs.tryletterhead.com/release-notes/2026-06-22-whats-new.md): 16 updates shipped during the week of Jun 22, 2026. - [What's new — week of Oct 12, 2026](https://docs.tryletterhead.com/release-notes/2026-10-12-whats-new.md): 10 updates shipped during the week of Oct 12, 2026. - [What's new — week of Oct 5, 2026](https://docs.tryletterhead.com/release-notes/2026-10-05-whats-new.md): 22 updates shipped during the week of Oct 5, 2026. - [What's new — week of Sep 14, 2026](https://docs.tryletterhead.com/release-notes/2026-09-14-whats-new.md): 9 updates shipped during the week of Sep 14, 2026. - [What's new — week of Sep 21, 2026](https://docs.tryletterhead.com/release-notes/2026-09-21-whats-new.md): 12 updates shipped during the week of Sep 21, 2026. - [What's new — week of Sep 28, 2026](https://docs.tryletterhead.com/release-notes/2026-09-28-whats-new.md): 11 updates shipped during the week of Sep 28, 2026. - [What's new — week of Sep 7, 2026](https://docs.tryletterhead.com/release-notes/2026-09-07-whats-new.md): 3 updates shipped during the week of Sep 7, 2026. ## Support - [Cancel your account](https://docs.tryletterhead.com/support/cancel-your-account.md): Cancel your Letterhead account and subscription by filling out the cancellation form with your name, email, account name, and reason. Requests are processed within 2–5 business days. - [Contact Support](https://docs.tryletterhead.com/support/contact-support.md): Chat with Letterhead support directly in the app — our support assistant Penpal answers right away and a human teammate joins the same thread when needed — or email support@tryletterhead.com. We respond to email within one business day. - [How can I request a new feature?](https://docs.tryletterhead.com/support/request-a-feature.md): We invite you to submit your ideas for feature requests to our Product team. - [How Can I Sign Up to Get Early Access to Letterhead's New Features?](https://docs.tryletterhead.com/support/early-access-new-features.md): Want early access to new features? Sign up as an Early Access tester! - [Service status notices now appear inside Letterhead](https://docs.tryletterhead.com/support/service-status-notices-now-appear-inside-letterhead.md): Service incidents and scheduled maintenance now appear as in-app notices, colour-coded by severity, with a link to the status page. ## FAQ - [As a subscriber, can I submit an article through Letterhead?](https://docs.tryletterhead.com/faq/as-a-subscriber-can-i-add-article-in-our-newsletter.md): The best way to submit an article to the newsletter's author is to reply to the newsletter with your article submission. - [Easter eggs](https://docs.tryletterhead.com/faq/easter-eggs.md): Type the Konami code (up, up, down, down, left, right, left, right, B, A) in Letterhead when you're not typing in a field and confetti bursts across your screen. It's just for fun and changes nothing in your account. - [How to Clear Cache and Cookies](https://docs.tryletterhead.com/faq/how-to-clear-cache-and-cookies.md): Learn how to clear your browser's cache and cookies to resolve loading issues and improve performance. - [How to Submit Data Requests](https://docs.tryletterhead.com/faq/how-to-manage-audience-data-requests-dsrs.md): Depending on your role, data requests such as exporting, updating, or deleting subscriber information can be handled either directly within the app or through our Support team. - [Tracking & UTM codes in Letterhead](https://docs.tryletterhead.com/faq/tracking.md): Explains Letterhead's own click-tracking codes and how to add your own UTM parameters to every link in an edition, using static values or personalization tags for dynamic, per-reader values. - [What Emojis Does Letterhead Support?](https://docs.tryletterhead.com/faq/emojis.md): This question isn't specifically about whether Letterhead supports emojis, but more broadly about how emojis are supported across different email platforms. - [What Happens If a Global Ad Was Scheduled but No Newsletter Was Sent?](https://docs.tryletterhead.com/faq/if-a-global-advertisement-was-planned-for-yesterday-but-the-newsletter-wasnt-distributed-will-it-be-automatically-included-in-todays-newsletter-our-practice-is-t-1694531430844.md): If a global promotion was scheduled for a day when no newsletter went out, it does not roll over automatically — you'll need to update its run date and re-approve it. - [What Permissions Does the Channel Administrator Have?](https://docs.tryletterhead.com/faq/what-permissions-does-the-channel-contributor-have.md): Understanding the Features and Limits of a Channel Administrator - [What Permissions Does the Content Contributor Have?](https://docs.tryletterhead.com/faq/content-contributor-role.md): Understanding the Permissions and Features Available to Content Contributors - [What Permissions Does the Organization Administrator Have?](https://docs.tryletterhead.com/faq/what-permissions-does-the-channel-administrator-have-1.md): Organization Administrators have full access to all channels, organization-wide settings, and account-level tools. - [When are welcome letters triggered?](https://docs.tryletterhead.com/faq/when-are-welcome-letters-triggered.md): This article outlines when welcome letters are triggered, and when they are not, so that you can set up your flows correctly. It also shows you how to trigger them via Zapier, if necessary. - [Why am I receiving DMARC Reports](https://docs.tryletterhead.com/faq/why-am-i-receiving-dmarc-reports.md): DMARC reports are automatically generated by email providers to show how your emails are being checked for legitimacy and whether they pass security checks. - [Why Can't I Include Attachments in My Newsletter?](https://docs.tryletterhead.com/faq/why-cant-i-send-an-attachment-with-my-newsletter.md): Attachments are not allowed in Letterhead in order to safeguard the deliverability of your emails. - [Why can't I upload an image to the image block?](https://docs.tryletterhead.com/faq/why-cant-i-upload-an-image-to-the-image-block.md): Learn more about how the image block works. - [Why does my antivirus give me a warning when I click on the links on the news page?](https://docs.tryletterhead.com/faq/when-i-try-to-access-one-of-the-links-on-your-news-page-i-get-a-warning-from-my-anti-virus.md): Sometimes, antivirus programs flag our tracking links as risky because they use heuristics or behavior analysis to detect potential threats. These methods are not always accurate and can result in false positives. ## Optional - [Every article in one file](https://docs.tryletterhead.com/llms-full.txt)