Sender reputation
Sender reputation is the running record a mailbox provider keeps about a sending domain or address, built from how recipients and receiving systems treated its past mail.
Read more4. Deliverability
What is domain warm-up?
Domain warm-up is the practice of raising how much a new sending domain and mailbox send per day in small steps, so mailbox providers see steady, wanted mail before they see volume. The messages are real, low-volume sends to real prospects.
The parts
- Start smallA mailbox with no history is sending its first messages anywhere. A handful of well-matched messages a day gives providers something clean to learn from.
- Step up on a scheduleEach week the daily cap rises a little. If bounces or complaints appear, hold the cap or step back until they stop.
- Real sends to real prospectsWarm-up here means ordinary outreach at a gentle pace. ColdMeetings does not offer mailboxes that email each other, because traffic that nobody reads teaches providers nothing true about you.
- Authentication comes firstSPF, DKIM and DMARC should pass before the first message. Warm-up on an unauthenticated domain only builds a poor record.
A new mailbox at Pinewick Software
Pinewick Software is an invented company with one new mailbox. ColdMeetings caps a mailbox by its age in days, so the schedule below is what that mailbox may send each day.
By hand
- Week 1 (mailbox age 0 days and up): up to 5 messages a day.
- Week 2 (mailbox age 7 days and up): up to 10 messages a day.
- Week 3 (mailbox age 14 days and up): up to 20 messages a day.
- Week 4 (mailbox age 21 days and up): up to 30 messages a day.
- Week 5 onward (mailbox age 28 days and up): up to 40 messages a day.
- Added up, the first four weeks allow 455 messages in total, sent to prospects who fit the target profile.
Daily send cap for one mailbox by week of age.
How to apply it
- Register the sending domain and publish its SPF, DKIM and DMARC records before the first send.
- Keep the first weeks to well-matched prospects with verified addresses, and let the daily cap rise on its schedule.
- Check bounces and replies each day. A rise in either is a signal to hold the cap, not to push through.
- Add more mailboxes for more capacity instead of forcing one mailbox past its cap.
Mistakes to avoid
- Using mailboxes that email each other to look busy. It builds no true record and it is not offered here.
- Jumping to full volume in week one because the first sends went well.
- Warming one mailbox, then sending from a different domain with no history.
Related terms
Bounce rate
Bounce rate is the portion of the emails you sent that came back undelivered.
Read moreSPF
SPF, short for Sender Policy Framework, is a DNS TXT record on your domain that lists the servers allowed to send mail using that domain.
Read moreQuestions
- How long does warm-up take?
- On the ColdMeetings schedule a mailbox reaches its full daily cap at 28 days of age, with the cap rising in a step each week before that.
- Can I skip warm-up if I use a brand new domain?
- A new domain has no history, so it is where a gradual start matters most. Google also advises that if messages start bouncing, you reduce volume and increase it slowly again.
- Does ColdMeetings offer mailboxes that warm each other up?
- No. We do not offer mailboxes that email each other. Volume rises only through real low-volume sends to real prospects.
Sources
- Google: Email sender guidelines: https://support.google.com/a/answer/81126, read 2026-10-19
- Yahoo: Sender best practices: https://senders.yahooinc.com/best-practices/, read 2026-10-19
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