Take the 2-minute tour ×
Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

I have someone with two domains, a.com and b.com.

a.com is running a postfix server on the mx host for the domain and I have total control of the server.

b.com is running an exchange server on the mx host for the domain and I do not have any control of this server.

They have been using b.com as their primary mail address and use the exchange calender with outlook.

They want all the same functionality but want to start using a.com as primary mail address.

I opened up postfix to allow relay from the ip address of the exchange server and hopefully that's enough from the outgoing side.

For delivery though what can I do to forward all incoming emails to the exchange server? I have some aliases defined in /etc/aliases that should take higher priority.

share|improve this question

1 Answer 1

up vote 2 down vote accepted

you'll need to set up a transport map for b.com http://www.postfix.org/postconf.5.html#transport_maps where the map consists of something like: b.com smtp:mail.b.com:25

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.