Warming up
Mailbox providers do not know a brand-new domain. A sudden jump from zero to thousands of emails looks like spam. Warming up means ramping volume over a few weeks so providers see steady, wanted mail first.
Rules of thumb
Section titled “Rules of thumb”- Start with your most engaged recipients: recent signups, active customers.
- Double the volume at most every day or two, and only while bounce and complaint rates stay low.
- Keep daily volume steady rather than spiky.
- Send each day at a similar time.
- Do not warm up with purchased or stale lists.
Example schedule
Section titled “Example schedule”For a domain that will eventually send about 50,000 emails a day:
| Day | Emails per day |
|---|---|
| 1 | 50 |
| 2 | 100 |
| 3 | 250 |
| 4 | 500 |
| 5 | 1,000 |
| 6 | 2,500 |
| 7 | 5,000 |
| 8 to 10 | 10,000 |
| 11 to 14 | 25,000 |
| 15+ | 50,000 |
Smaller senders simply stop earlier. Slow down if any day shows more than 2% bounces or 0.1% complaints.
How this fits with SpacePost limits
Section titled “How this fits with SpacePost limits”- New teams are in the sandbox (100 per day) for 7 days, which doubles as a natural warm-up.
- Your daily cap then follows your trust level: it grows with your actual sending, at most 2x your best recent day.
- Use a separate subdomain per mail stream so a problem with marketing mail cannot hurt password resets.
Monitor while you warm up
Section titled “Monitor while you warm up”Subscribe to email.bounced and email.complained webhooks and look at the Gmail Postmaster Tools dashboard for your domain (domain reputation, spam rate).