==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 1.6.2 MARIADB edition.
- Deployed with iRedMail Easy or the downloadable installer? Downloadable
- Linux/BSD distribution name and version: Rocky Linux  8.7
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro?
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

Hi to everyone !
Question like this was here once, but answer is not completely understandable.

I am using mail server as secondary mail server for office365 users to froward mail from authenticated users via smtp.

as example
scanner01.domain.net ( has username and password)

Mail flow outside is good: 'man@gmail.com' is getting the mail.
But when someone is trying to send inside this domain ( to accounts@domain.net) it fails, because this mailbox is not present on server and it is on office 365.

The Question!
How is possible to omit local mailbox lookup and forward mail outside ?