Warming up your sending reputation
Edit in CMSMailbox providers decide where your email lands partly on your track record as a sender. Warming up means building that track record gradually, so providers see steady, wanted mail rather than a sudden flood. How much of it you need to do depends on how you send. None of these steps can guarantee inbox placement, but they give your first sends the best start.
On shared IPs, you don’t need to warm up an IP
Section titled “On shared IPs, you don’t need to warm up an IP”Most Letterhead customers send from shared IP pools that are already warm, so there’s no IP warm-up to do and you can send to your full list from your first newsletter.
Your domain still builds a reputation
Section titled “Your domain still builds a reputation”Providers judge your sending domain as well as the IP it sends from. When you move to Letterhead, your domain’s reputation comes with you, but providers watch how it behaves on the new platform. If your list is large, or you’re not sure how clean it is, ramp up gradually rather than sending to everyone at once. For example, send to 10,000 readers a day, then 20,000 the following week, then 50,000, until you reach your full list. Start with your most engaged readers, the ones who’ve opened or clicked recently.
If you’re setting up a brand-new sending domain on a company-level email connection, Letterhead can warm it up for you, adding readers a day at a time. See Warming up a new sending domain.
If you’re unsure about your list
Section titled “If you’re unsure about your list”Letterhead doesn’t check every address before it sends. If your list may contain a lot of dead addresses, your first newsletter can show a high bounce count, and those bounces count against your reputation. Two ways to start carefully:
- Ramp up gradually, as above, so a bad batch is a small one.
- Send a re-opt-in first. Import your readers with a
Pendingtag, make a segment of that tag, and send that segment a short email from your new Letterhead account letting them know they’re subscribed and can unsubscribe if they no longer want your newsletter. This also helps if you’re unsure everyone deliberately opted in.
Recipient Validation, a paid feature your Account Manager can turn on, checks new addresses from imports, embed forms and archive signups once a day. It confirms an address is real, not that its owner opted in, and it can’t be run on demand right before a send.
Dedicated IPs need a planned warm-up
Section titled “Dedicated IPs need a planned warm-up”A dedicated IP (an enterprise feature) sends only your mail, so it starts with no reputation at all and has to be warmed on a schedule. Your Account Manager will plan this with you. A typical schedule:
| When | How much to send |
|---|---|
| Days 1–3 | 0.5–1% of your list a day, starting with 20–50 emails to your most engaged readers |
| Days 4–7 | 1–2% of your list, adding readers who are less active but still engaged |
| Week 2 | 5–10% of your list |
| Week 3 | 10–20% of your list, keeping engagement high |
| Week 4 onward | Build up to your full volume |
For a list under 10,000 readers you can use shorter steps; for one over 100,000, stretch the warm-up out and grow more slowly. If you send weekly or monthly, grow the volume with each newsletter rather than each day.
When to contact us
Section titled “When to contact us”If you’ve ramped up steadily and your bounce or complaint numbers are still climbing, or a mailbox provider is refusing your mail, contact [email protected] and we’ll look into it.
Related
Section titled “Related”Still can’t find what you need? Contact support.