Topic: Problem with mail relayed by Office365 in the same domain
==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 1.0 MARIADB edition
- Deployed with iRedMail Easy or the downloadable installer? downloadable installer
- Linux/BSD distribution name and version: Debian 10 - Debian 4.19.67-2+deb10u2 (2019-11-11) x86_64 GNU/Linux
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MariaDB
- 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.
====
Hello,
in my configuration there are two mail servers: Office365 and iRedMAil. They are supporting the same domain, one part account are supporting by Office and 2nd part by Postfix.
@mydomain.com MX record is set to Office365 service. Office365 relay is configure the way that if mailbox does not exists, forward to Postfix (smarthost).
My O365 users accounts:
one@mydomain.com
two@mydomain.comMy Postfix users accounts:
one@mydomain.com
two@mydomain.com
three@mydomain.comIf someone from Internet (other domain, other server) sends e-mail to three@mydomain.com -> delivered correctly on Postfix.
The problem is when one@mydomain.com (O365 in the same domain) or two@mydomain.com(O365 in the same domain) sends mail to three@mydomain.com. Office365 try relay mail to Postfix, but postfix bouncing with:
554 5.7.1 <three@mydomain.com>: Recipient address rejected: SMTP AUTH is required for users under this sender domainPlease help me to allow Office365 use the same sender domain as Postfix supporting.
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