I'm revisiting this issue after a break - about a year - and now I'm
trying to get to the bottom of this. I found a thread from five years
back (<a href="http://bit.ly/bIFigX" title="http://bit.ly/bIFigX">http://bit.ly/bIFigX</a>) that discusses a similar issue, but my
situation is somewhat different.
I'm attempting to create a configuration where mail from a set of
local domains is delivered through an external relay while all other
mail (i.e. anything but the listed domains) would be relayed directly
to the receiving remote smtp servers. I would essentially want to
make the "relayshost" parameter conditional per specific domain names:
defined for some (for external relaying), and blank for some (for
It may be that the only way to accomplish this is to run two separate
Postfix instances, one configured with relayhost, accepting outbound
mail for those domains that should be relayed via a remote host, and
the other configured without relayhost, accepting outbound mail for
all other relayable domains.
Before embarking on the multiple instances route, however, I wanted to
see if anyone on the list would have a solution that would make this
possible with a single Postfix instance.
Thanks for any advise & insights on this issue!