==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 1.3.2
- Deployed with iRedMail Easy or the downloadable installer?
- Linux/BSD distribution name and version: Ubuntu 18
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): Mysql
- 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 have hosted same domain on two different iredmail server, For sending newsletter i have create 2 email account on second server, but when i am sending mail from that account on email ids of same domain on different server, i am getting error.

recipient address rejected: user unknown in virtual mailbox table

I know this error because of it is trying to sent mail locally, i am getting above error

To solve this error, i have added transport and relay_recipients files and added entry in main.cf as below : relay_recipient_maps = hash:/etc/postfix/relay_recipients
transport_maps = hash:/etc/postfix/transport

Also added email ids in both files repeciverly.
test@example.com OK
test@example.com smtp:mail1.example.com:25

Have done postmap and restarted postfix.

With same settings i am able to route different domains mails on different servers. but here still mails are bouncing with recipient address rejected: reason.

I have verify all settings many times, i am not getting what i am missing here.

Can you please help me in this matter.

Thanks in advance.