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You need your SMTP username, password, and relay hostname from your mySMTP setup email.

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Before you start

Have these details ready:
Use the exact relay hostname from your setup email. relayxx.mysmtp.com is only an example.
1

Open SMTP delivery settings

In hMailServer Administrator, go to Settings > Protocols > SMTP > Delivery of e-mail.
2

Set the remote host name and port

  1. Enter your relay hostname (e.g. relayxx.mysmtp.com) in Remote host name.
  2. Enter 587 in Remote TCP/IP port.
3

Enable SMTP authentication

  1. Check Server requires authentication.
  2. Enter your mySMTP username and password.
4

Set connection security

Select STARTTLS (Required) from the Connection security dropdown. If STARTTLS is not available as an option, set it to TLS or the nearest equivalent and ensure the port is 587.
5

Save and test

Click Save and send a test email from a client connected to hMailServer.
Menu labels may vary slightly depending on your hMailServer version. Look for “Delivery of e-mail” or “SMTP routes” under the SMTP protocol settings.

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Test the connection

  1. Send a test email from a mailbox on your server to an external address, such as a Gmail account or your own.
  2. Confirm the message arrives. In the received message headers you should see it passed through your mySMTP relay.
  3. If the message does not arrive, check the server’s mail queue or logs for delivery errors.

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Troubleshooting

Re-enter your mySMTP username and password in the smart host settings. Make sure there are no extra spaces.
Check that outbound traffic on port 587 is allowed by your firewall. Try port 2525 if port 587 is blocked, and update the port in your server settings.
If your server version does not support STARTTLS, confirm you are using a current release. hMailServer and MDaemon both support TLS on SMTP delivery in recent versions.
Make sure the sender address uses a domain authenticated for your mySMTP account. See DNS settings quick explainer.
For more error codes, see Common SMTP errors.