==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release):
1.3.1 PGSQL edition.
- Deployed with iRedMail Easy or the downloadable installer?
Installer
- Linux/BSD distribution name and version:
Ubuntu 20.04
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):
PGSQL
- Web server (Apache or Nginx):
Nginx
- Manage mail accounts with iRedAdmin-Pro?
No
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

I'm having a hell of a time trying to configure two web sites (one on the lan, the other external) to send mail through iredmail.

I have a primary domain of infoteq.com.au, with several aliased domains (intq.it, gpsit.com.au, goldenplainsit.com.au) which all seem to be able to receive mail OK, and thunderbird has no issues sending mail out through this mailer either.

However, the sites no so much.

If I use the default php mail client on the systems the mails all bounce with

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

  pnunn@infoteq.com.au
    host mail3.infoteq.com.au [119.17.137.218]
    SMTP error from remote mail server after RCPT TO:<pnunn@infoteq.com.au>:
    554 5.7.1 <pnunn@infoteq.com.au>: Recipient address rejected:
    SMTP AUTH is required for users under this sender domain

Reporting-MTA: dns; se2-mel.hostedmail.net.au

Action: failed
Final-Recipient: rfc822;pnunn@infoteq.com.au
Status: 5.0.0
Remote-MTA: dns; mail3.infoteq.com.au
Diagnostic-Code: smtp; 554 5.7.1 <pnunn@infoteq.com.au>: Recipient address rejected: SMTP AUTH is required for users under this sender domain

Test message from Golden Plains IT.eml
Subject:
Test message from Golden Plains IT
From:
GPSIT Website <pnunn@infoteq.com.au>
Date:
4/12/2020 3:00 PM
To:
pnunn@infoteq.com.au

This is a test message.

Configuration:
- Send mail method: php_mail

and it doesn't seem to matter what address I set as the sending address, they all have the same SMTP AUTH error.

If I try and configure the sites to use mail3.infoteq.com.au as the smtp host, I get errors about the certificates (see the two attached screen shots).

I'm at a loss how to get this working.