I'm trying to set up a redundant "store-and-forward" mail server.
This box will reside much farther towards our network periphery
than the present Exchange server we are currently using. We will
set up a *secondary* MX record for it in DNS, so mail will only
go to it if the primary is unavailable. If we lose a critical
internal network node for, say, a day or two, the intent is that
this box will act as a "cache" until connectivity is restored,
then will forward the email it has been storing to the again-
available Exchange server.
I seem to have qmail running now .. thanks, again, to Greg Owen.
The problem now is how to set it up to *forward* mail to
*another* server. Paul Gregg's Single UID Mailbox HOWTO, at
http://www.tibus.net/pgregg/projects/qmail/single-uid-howto.html,
really does not seem to be what I am looking for, since it seems
to require a distinct entry in /var/qmail/users/assign for each
individual user. This is perfect for a situation where the
server is being used to manage POP-3 accounts, but the management
problems of this approach for a domain with, perhaps 300 to 400
users, whose accounts are really managed at the Exchange server,
are unreasonable.
What I need is a configuration such that *all* emails coming into
the foo.com domain will be stored and, once the network link to
the primary server is back up, will be forwarded. There doesn't
seem to be any information at http://www.qmail.org/top.html about
how to do *that*.
Has anyone done something like this using qmail? Any pointers to
configuration data would be much appreciated.
Thanks,
Charles