Postfix: relay mail to smart host for specifc users

Question

Currently i have a VPS that has a host of email accounts on for several domains.

most are simple and have all local mailboxes.

but i have one user that wants to have a hosted exchange account but leave all the others as they are.

So what i would like to do is:

Domain1.com - Deliver all mail localy (as it currently does)

Domain2.com - [email protected] -> send to smart.host1.com - all others treated as local.

then there is also a possibilty that i could have:

Domain3.com - [email protected] -> send to smart.host1.com - [email protected] -> send to smart.host2.com - all others treated as local.

it also may use useful if i could specify a outgoing smarthost per domain name.

Im sure this has to be possible.

Hope this makes sense!

Solution

This can be achieved with transport_maps = hash:/etc/postfix/transport in main.cf

#/etc/postfix/transport
domain1.com     local:
[email protected]       smtp:smart.host1.com:25
domain2.com             local:
[email protected]       smtp:smart.host1.com:25
[email protected]       smtp:smart.host2.com:25
domain3.com             local:

Comments

[Steve Taylor]

I cant seem to get this to work, Currently i have got relayhost = outbound.smarthost.com would this effect any of the above?

[clement]

Please see postconf transport_maps override relayhost parameter. U can have a * smtp:outbound.smarthost.com:25 line in your transport file as a workaround

[Kalle Richter]

It's necessary to run postmap /etc/postfix/transport and restart the service or at least invoke service postfix reload after creating transport and changing main.cf.