Resolved emails to local domains not being delivered

[zoni]

Hello, I need some help please,

Here is my situation:

Emails from domain1 to domain2 are not being delivered.

Domain2 has email service by google apps and both domain1 and domain2 are hosted in the same server.

Postfix is delivering email through a relay server and it sends emails to domain2 internally and as a consequence is shows this message: "Recipient address rejected: User unknown in virtual mailbox table", which is true once domain2 has google hosted email and the user is not created locally.

This started to happen recently and I have never had this problem before, I think the cause is a recent update in postfix.

In plesk how do I tell postfix to send emails to local domains through the relay server instead of sending them internally?

Thanks