Warm up your Postmark mailboxes with MailPilot
MailPilot warms up Postmark mailboxes over SMTP using your Postmark server token as the credential, with IMAP for reply detection. Postmark is built around strict separation of transactional and broadcast streams and is known for high deliverability — but that reputation is Postmark's, not yours, and cold outreach belongs on a Broadcast message stream that still needs your domain warmed. MailPilot sends warmup traffic through your Postmark Broadcast stream to build the domain history that keeps outreach out of spam.
How it works with Postmark
Use a Broadcast message stream
Create or select a Broadcast stream in Postmark (not the transactional stream) for outreach, and grab that server's API token.
Connect over SMTP
Point MailPilot at smtp.postmarkapp.com on port 587, using your Postmark server token as both the SMTP username and password.
Verify your sender signature
Confirm your domain's sender signature and DKIM in Postmark, and add DMARC. MailPilot checks authentication so warmup mail is signed by your domain.
Warm and monitor
MailPilot ramps warmup volume on the Broadcast stream and reports inbox placement so you know when the mailbox is ready for real campaigns.
Why warm up Postmark
Postmark's excellent deliverability reputation belongs to Postmark's infrastructure — your specific sending domain still starts cold and needs its own history built through warmup.
Postmark separates transactional and Broadcast streams for good reason; cold outreach must run on a Broadcast stream, and that stream's domain reputation is what warmup develops.
Postmark enforces low bounce and complaint tolerances to protect its network. A warmed mailbox produces clean engagement, keeping you compliant and your stream in good standing.
Postmark warmup FAQ
Which Postmark stream should I warm up for cold outreach? +
Always a Broadcast message stream, never the transactional stream. Postmark keeps them separate on purpose, and outreach on the wrong stream risks account issues. MailPilot sends warmup traffic on the Broadcast stream you designate.
What are the Postmark SMTP settings? +
Use host smtp.postmarkapp.com, port 587, with your Postmark server API token as both the username and password. MailPilot also needs IMAP access to the receiving mailbox for reply handling and de-spamming.
If Postmark already has great deliverability, why warm up? +
Postmark's reputation covers its shared infrastructure, but mailbox providers still evaluate your individual sending domain. A brand-new domain has no history, so warmup builds the domain-level trust that determines inbox vs. spam for your outreach.
Warm up Postmark the right way
Free plan available. 14-day trial on paid plans, from $9/mo. No credit card. Connect your Postmark mailbox in minutes.
Get started free →