Warming Up New SMTP Accounts

A fresh SMTP account without sending history is like a new social media account. If you post 100 times a day right away, it will get banned. It's the same with email: sending 1000 emails from a new Gmail account on the first day is a guaranteed path to spam.

What is warmup

Warmup is a gradual increase in sending volumes from a new account. The goal is to accustom mail providers to the fact that a regular stream of normal quality emails is coming from you, without spikes and without complaints.

Basic 30-day warmup plan

• Days 1-3: 5-10 emails/day. Only to addresses that reply (friends, colleagues, test inboxes). All emails must receive a reply - this is a key metric
• Days 4-7: 15-25 emails/day. You can start including real recipients, but in small lists
• Days 8-14: 30-50 emails/day. Gradually increase the volume, keeping the bounce rate below 2%
• Days 15-21: 60-100 emails/day. You can start full-fledged mailings, but carefully
• Days 22-30: 100-200 emails/day - stable mode
• After 30 days: you can reach the provider's maximum limit

What is important during warmup

1. Get replies - replying addressees are the strongest reputation signal. Especially in the first week
2. Opens and clicks - all interactions with emails raise the score. Therefore, send the first emails to those who will definitely read them
3. Clean base - bounce > 5% during warmup will kill the reputation instantly. Run the addresses through an email-validator before sending
4. No links in the first 7-10 days. At all. One URL in an email on a fresh account is a reason for suspicion
5. Regularity - better 20 emails every day than 100 times a week and silence

Automatic warmup

There are automatic warmup services (Mailwarm, Warmup Inbox, Warmy, etc.) - they exchange emails between connected accounts and emulate positive engagement (open, reply). This speeds up the process from 30 to 14 days. Postigo does not prohibit the use of such services in parallel with regular sending - they complement each other.

Continuous monitoring

The Postigo dashboard on the main page shows the SMTP capacity widget: how many emails have been sent today, what % of the limit. Do not exceed the set daily limit even after warming up - this is part of normal sending.

If the bounce rate starts to rise above 3% - pause for 1-2 days and check the database. Sharp drops in open-rate are a signal that the reputation is falling.