I have solved the issue.

Apparently I needed to restart zimbra to get the new settings in.

Would be nice if the setting would have automatically been populated into postfix, but it works now :)

OK, an update.

I just went through all the steps described at ZimbraMtaMyNetworks - Zimbra :: Wiki and I found that the zimbra settings do not seem to be the same as the postfix settings:



$...

I am having an issue with sending emails in my setup.

My server is setup, and everything works fine. All users can send and receive emails. However, I have another server that tries to relay...