SMTP Relay Port 25

I have a legacy piece of software that sends simple alert messages via email. It does not allow changing the outgoing smtp port from 25.

Is there anyway to get Mail-in-a-box to accept messages on port 25 with authentication but without TLS?

Is your app and mail server internal to your network?

No, my MIAB instance runs on Linode cloud. I do have root access to it.

I think the answer is within this page:

https://docs.iredmail.org/enable.smtp.auth.on.port.25.html

Note that changes to main.cf will be commented out and a new default line created with MiaB version updates.

Just out of curiosity, any plans on dealing plain text passwords? Seems like the option of an SMTP relay between your app and your server would be a better solution.

I agree completely. There are threads on the forum which discuss relay options for printers / scanners / etc. Same concept.