==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release):  iRedAdmin-Pro-LDAP 3.1
- Deployed with iRedMail Easy or the downloadable installer? Installer
- Linux/BSD distribution name and version: 
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):
- Web server (Apache or Nginx):
- Manage mail accounts with iRedAdmin-Pro? Yes
- [IMPORTANT] Related original log or error message i s required if you're experiencing an issue.
====

So we have a domain which we are using on multiple servers - and we have an iRedmail server is the mailserver for them (receiving).

However, it can't receive from any domain which is listed on the domain lists of the server for mail without being authenticated, I was pushed towards this: https://docs.iredmail.org/errors.html#r … er-domain.

An example - we send out a newsletter - everyone gets it apart from anyone internally as it's blocked.

We get this error message:

The original message was received at Fri, 31 Jul 2020 00:00:00 +0100 (BST) from localhost [127.0.0.1]

   ----- The following addresses had permanent fatal errors ----- <XYZ>@****>
    (reason: 554 5.7.1 <license@boxfx.co.uk>: Recipient address rejected: SMTP AUTH is required for users under this sender domain)

   ----- Transcript of session follows ----- ... while talking to mail.@****.co.uk.:
>>> DATA
<<< 554 5.7.1 <lXYZ@****.co.uk>: Recipient address rejected: SMTP AUTH is required for users under this sender domain
554 5.0.0 Service unavailable
<<< 554 5.5.1 Error: no valid recipients

We have done it - but it's still not getting the mails - any suggestions?