Question Relay redirected email

[EnriqueR]

I have the system set so that when the customer sends an email, postfix send messages from certain sender domains by an external system relay. The problem is that when I set up an email to be forwarded to another email account, eg Gmail, the system does not use the relay system to send it.

Example:
Email from email@internal.com to email@gmail.com -> Use relay system
Email from email@external.com to email@internal.com. Redirects to email@gmail.com without using relay system.

How could I do to tell the system to use this relay system for forwarded messages through postfix and dovecot?

 

[EnriqueR]

Any solution for my email forwarding problem??

 

[EnriqueR]

I have found a solution. I need to create two Postfix instances. The first filters the senders and the second filters the recipients.

My question is, if I create two instances. Will Postfix still work properly with Plesk? Will it still be fully compatible with Plesk?