postfix: smarthost/relayhost for particular domain?
Jem Berkes
domains except (ironically) for when sending to my own ISP's email
addresses. Their MX doesn't accept incoming TCP connections from my host,
and I have no clue why.
While their domain's MX doesn't accept my connections, there are other
hosts that will; for instance, the SMTP server address that customers are
supposed to use. I was going to enable postfix's relayhost feature (like
sendmail smarthost) but this would send ALL outgoing mail through
smtp.myisp
However I really only want to resort to this type of mail delivery when the
recipient is at that particular ISP, since this is the only domain that
causes problems. Is there a way to make relahost= work for only a certain
recipient domain?
--
Jem Berkes
http://www.sysdesign.ca/
Jem Berkes
> hosts that will; for instance, the SMTP server address that customers
> are supposed to use. I was going to enable postfix's relayhost feature
> (like sendmail smarthost) but this would send ALL outgoing mail
> through smtp.myisp
I have found the solution (postfix is awesome!). To help out anyone who
wants to do something similar, relaying mail bound to specific addresses or
domains through a specific mail relay, here is what you do:
1. Edit /etc/postfix/transport. Here is what I added:
mts.net smtp:[smtp.mts.net]
This means: when the destination is @mts.net, send mail through
relay host smtp.mts.net. The host name is in brackets to disable MX
lookup; my intent is to use exactly that specified mail relay to
solve a quirky connectivity problem I have to the proper MX.
2. Run 'postmap /etc/postfix/transport' to update the db (mine is hash)
3. In /etc/postfix/main.cf, enable transport_maps
transport_maps = hash:/etc/postfix/transport
In my case the map is a hash file, adjust as necessary. For more detail see
'man transport' for the syntax of the transport mappings. This is a very
powerful feature!