Hi,
I'm in the process of replacing a server running Postfix with Exim, due to
obvious reasons. Now I have in principle the following configuration:
- smtp-in machine accepts in connections to port 25, runs greylistd, and
then forwards the messages forward to a machine. I'm not 100% sure how
this was accomplished, and the machine is not in my appartment at the
moment, but it was the hubbed.hosts or hubbed_hosts for the hubbed
router definition. Anyways, the file has a number of domains, and a
smtp server for each domain to send the mail to. This machine cannot
connect to port 25 outside on the internet.
- mailserver is a machine running Exim, that receives in practice all the
hubbed mail from the smtp-in machine, for all domains. This machine
delivers the mail to the local machine.
- smtp-out is a machine running Exim, which can make connections outbound
to port 25, so it can send mail to the outside world.
So, my dilemma is this, which I would really appreciate an answer for, how
can I convince the smtp-in machine to send the hubbed router stuff _first_,
and if something goes wrong, a bounce is sent back to the sender via the
smtp-out machine, which acts as a smart host for smtp-in and mailserver?
I think that if I do use the smarthost feature without the hubbed router,
I will end up in a situation, where the mail starts to just circulate
between the smtp-in and smtp-out machines, because smtp-in is MX for the
domains, and smtp-out will obviously send there the mail without thinking
anything about it.
So, is it possible to force Exim to first act on the hubbed router, and
deliver mail straight to a given smtp server, with a direct connection
to the port 25, and then if the hubbed router fails, it resorts back to
using smtp-out as the smart host for sending mail? If this is possible,
how would I go ahead and configure it?
I'm new to this list, and I'm really sorry if I asked a FAQ, but google
hasn't told me essentially nothing for 2 hours.
Thank you,
Bo Granlund
