How to Warm Up a New Sending Domain (With a 4-Week Schedule)
To warm up a new sending domain, start with a few hundred emails a day to your most engaged subscribers, then roughly double volume every few days while bounces and complaints stay low. Most senders reach full volume in 3–4 weeks. Inbox providers trust domains that build volume gradually with mail people actually open.
Why does a new domain need warming up?
Gmail, Outlook and Yahoo judge senders by history. A new domain has none, so a sudden blast of 50,000 emails looks like spam, even if every recipient opted in. Warming up builds a track record of wanted mail first.
Who should I email first?
Your most engaged people: those who opened or clicked in the last 30–60 days. Their opens and replies send positive signals. Leave old or inactive contacts until the end, or remove them.
A sample 4-week warmup schedule
A common starting point, not an official rule. Slow down if you see warning signs.
| Days | Emails per day | Who to send to |
|---|---|---|
| 1–2 | 200 | Most engaged (opened in last 30 days) |
| 3–4 | 500 | Most engaged |
| 5–7 | 1,000 | Engaged in last 60 days |
| 8–10 | 2,500 | Engaged in last 90 days |
| 11–14 | 5,000 | Active in last 6 months |
| 15–21 | 10,000–20,000 | All active subscribers |
| 22–28 | Full list | Everyone, minus 12-month inactives |
Also respect your sending service's limits. On Amazon SES, your daily quota and send rate rise as AWS sees good results.
What warning signs mean I should slow down?
- Hard bounce rate above 2%
- Spam complaint rate approaching 0.1%
- Gmail deferrals or rate-limit errors in your logs
- Open rate dropping sharply from one day to the next
- Google Postmaster Tools showing domain reputation falling
If you see these, hold volume steady for a few days, check list quality, and only then continue.
Should I use an automated warmup service?
Avoid services that fake engagement by sending between networks of inboxes that auto-open and reply. Mailbox providers increasingly detect this, and it can hurt your reputation. Real warmup means real subscribers who want your email.
What else should be ready before day 1?
- SPF, DKIM and DMARC passing; see SPF, DKIM and DMARC for SES
- One-click unsubscribe in every marketing email
- Bounces and complaints suppressed automatically
- A cleaned list, with no purchased or scraped addresses
FAQ
How long does domain warmup take?
Usually 2–4 weeks, longer for very large lists or after a reputation problem.
Do I need to warm up if I use SES shared IPs?
Yes. Shared IPs have reputation, but your domain still has none. Gmail tracks domain reputation separately.
Can I warm up with a different domain and switch later?
Reputation is tied to the domain you send from. Switching domains means starting again.
Should transactional email go through the same domain?
Ideally use a separate subdomain, so a marketing problem never blocks password resets.