Configuring transport tables to relay emails to a different mail server. In this example I am forwarding all emails for otherdomain.com to smtp.otherdomain.com . You can add as many transport maps as you need. All commands should be run as a user 'zimbra'. After 5.0.9, postfix_transport_maps has been modified a bit, so we'll show both ways.
$ zmlocalconfig |grep -i postfix_transport_maps
This will show you the current transport maps file configuration:
postfix_transport_maps = ldap:/opt/zimbra/conf/ldap-transport.cf
or for Zimbra 5.0.9 and higher (including 6.0):
postfix_transport_maps = proxy:ldap:/opt/zimbra/conf/ldap-transport.cf
Create your transport file (owner/group-owner should be zimbra):
vi /opt/zimbra/postfix/conf/transportfile otherdomain.com :[smtp.otherdomain.com]
You can also add multiple transport maps, for example:
mydomain.com :[mail.otherdomain.com] mydomain.org :[mail.otherdomain.com] hisdomain.net :[mail.otherdomain.com]
In this example all emails for 3 different domains will go to mail.otherdomain.com, so destination will be changed, while user name will remain as in original email address.
Convert the transport file into maptype database file:
$ postmap /opt/zimbra/postfix/conf/transportfile
The file transportfile.db will be created in this directory. Define the new transport file (original, not *.db one) BEFORE the default one. Run:
$ zmlocalconfig -e postfix_transport_maps="hash:/opt/zimbra/postfix/conf/transportfile ldap:/opt/zimbra/conf/ldap-transport.cf"
Or for Zimbra 5.0.9 and higher:
$ zmlocalconfig -e postfix_transport_maps="hash:/opt/zimbra/postfix/conf/transportfile proxy:ldap:/opt/zimbra/conf/ldap-transport.cf"
Finally, make sure that the relay_domains parameter in main.cf contains all domains handled by the server, whether locally or relayed elsewhere:
$ vi /opt/zimbra/postfix/conf/main.cf relay_domains = otherdomain.com, mydomain.com, mydomain.org, hisdomain.net, locallyhandleddomain.com, localaliaseddomain.com
Restart Zimbra:
zmcontrol stop zmcontrol start
