==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): v1.5.1
- Deployed with iRedMail Easy or the downloadable installer? EE Version
- Linux/BSD distribution name and version: 24.04.3 LTS
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro? YES
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

I have setup an email address on our server that forwards to three other emails (2 of the 3 are external email addresses i.e. not on our iRedmail server, and 1 of the three is on our server).  It does not have the Save a copy in mailbox checked.

When an email is received from an address that is hosted on the mail server, the email is correctly forwarded to each of the three recipients, however if an email is received from an address that is external (i.e. not on our email server) then the email is only forwarded to the one of the three recipients that is on our server.

Example:
Email Test No 1 sent from external address to forwarding email account -> delivered to one recipient (local on iRedMail server)
Email Test No 2 send from iRedmail local address to forwarding email account -> delivered to all three recipients  including the two external emails

Why does this happen and can it be fixed, as we would like the forwarding to always deliver to all three recipients?

Thanks,
Stephen