How to Warm Up a New Sending Domain
A new domain has no reputation. A four-week plan to build it safely and what to watch while you do.
In this article
A brand-new sending domain or IP has no history, so providers treat it cautiously. Warming it up means building a good history gradually.
Before you start
- Publish SPF, DKIM and DMARC and confirm they pass.
- Verify every address you plan to send to.
- Prepare engaged contacts first: customers, recent sign-ups and people who replied before.
A four-week plan
- Week 1: 20 to 50 messages a day to your most engaged contacts.
- Week 2: double the volume if bounce and complaint rates stay very low.
- Week 3: double again and add more segments.
- Week 4: move toward your normal volume.
These numbers are a guide; slow down at the first sign of trouble.
What to watch
- Bounce rate under 2%
- Complaint rate well under 0.1%
- Replies and clicks, not only opens
- Placement in test inboxes
Mistakes to avoid
- Sending a large campaign on day one
- Mixing cold and marketing mail on the same domain
- Skipping verification of the first lists
Start every warm-up with a verified list from the bulk verifier.
An example ramp, week by week
The numbers below are illustrative. Adjust to your list size and watch the signals each day.
| Week | Daily volume (per sending domain) | Who to send to |
|---|---|---|
| 1 | 50 to 100 | your most engaged contacts and colleagues |
| 2 | 200 to 400 | contacts who opened or clicked in the last 60 days |
| 3 | 500 to 1,000 | the wider active list, verified first |
| 4 | 1,500 to 3,000 | the rest of the active list, in stages |
Increase only when the previous step shows bounces under 2% and almost no complaints. If a day goes badly, step back to the last volume that worked and hold it for a few days.
Signals to watch
- Bounce rate per day, not just per campaign.
- Complaint rate in your tool's feedback loop data and in Google Postmaster Tools if available.
- Placement: send test messages to your own accounts at Gmail, Outlook and Yahoo and note whether they land in the inbox.
Warm-up mistakes
- Verifying the list late, so the first big batch bounces.
- Switching content, template and domain all at once, which hides the cause of a problem.
- Warming up with purchased or unfamiliar addresses.
- Stopping the warm-up after week four and then jumping to full volume.
Warm-up depends on a clean list from the start, so verify the whole audience before step one.
Mailbite Editorial TeamPractical guides on email verification and deliverability.