How To Warm A New Sending Domain Without Burning It
A week-by-week ramp for new domains and inboxes, with the signals that tell you to slow down.
A new domain has no history, and mailbox providers treat no history as a risk. Warmup is how you build a record of real sending before you ask the inbox to trust you with volume.
Start With Authentication
Before a single message goes out, SPF, DKIM and DMARC must pass on the sending domain. Send a test to a mailbox you control and read the headers. If any of the three fails, stop and fix it. Warming on top of broken authentication builds the wrong reputation.
The Ramp
- Week one: 10 to 15 messages a day per inbox, all to real contacts who will reply or at least open.
- Week two: 20 to 30 a day. Keep replies coming in. A thread with back and forth counts for more than ten one-way sends.
- Week three: 40 a day. Start mixing in cold sends at about one in four.
- Week four: 50 to 60 a day, half cold. Hold here until two weeks pass without a bounce spike.
Kill Conditions
Write these down before you start, so you are not negotiating with yourself later. Pause an inbox when bounces pass 3 percent in a day, when two or more messages land in spam during seed tests, or when a provider returns a throttling error. Drop volume by half for three days, then resume the ramp one step back.
What Not To Do
Do not buy a warmup network and walk away. Do not jump from 20 to 200 because a week went well. Do not send the same message to everyone. Warmup is slow on purpose, and the teams that rush it end up buying a new domain a month later.
Want help with setup? The Deliverability Fix Kit.
More on this: The Deliverability Playbook.