Postmark SMTP and IMAP settings
SMTP relay settings for Postmark, where the Server API token is used as both username and password.
Outgoing mail (SMTP)
| SMTP server | smtp.postmarkapp.com |
|---|---|
| Port | 587 (STARTTLS) or 2525 (STARTTLS) |
| Username | Your Server API token (used as both username and password) |
| Password | See authentication note below |
Authentication
Postmark uses your Server API token as both the SMTP username and password. Port 25 also works. Postmark is transactional-first and does not allow cold or bulk outreach.
How to set up Postmark in your email tool
- Open your email client or sending tool and add a new account.
- For outgoing mail, enter the SMTP server smtp.postmarkapp.com on port 587 (STARTTLS) or 2525 (STARTTLS).
- Set the username to your server api token (used as both username and password), and use the password described in the authentication note above.
- Save the account and send a test email to confirm it works.
Connecting is the easy part. Landing in the inbox is not.
Once Postmark is connected you can send, but whether your cold email reaches the inbox depends on SPF, DKIM, and DMARC authentication, your sender reputation, and proper domain warmup. Scheduler Zero handles warmup and deliverability so your emails actually land.