[Pkg-exim4-users] Suggestion for catch-all / smtp forwarder setup?

[Michael Schmitt]

Hi list,

I think about setting up exim4 on a wheezy box to work as a incoming 
relay for an evil MS exchange mailserver. It would be put in a DMZ-like 
area, would have an ipv4 IP-address and "real" host-/domain-name. As the 
internet connection drops sometimes (from time to time that connection 
is flaky like hell) I have to let another box get the mail when the 
connection is down. My idea is to set up a high priority (mx-entry in 
dns) for this host and a lower for another box with a more stable 
connection. After the connection is established again, I need to get the 
mail from that host. I guess getmail will do the job there. 
Spam-filtering (marking spam in the subject, nothing else) is another 
thing I think about, but I guess that shouldn't be a problem at all.
As of now I never used / set-up a catch-all box and want to hear if my 
idea is sane and maybe get some suggestions that might help me set it 
up. A general point in the right direction documentation-wise is fine too.

regards
Michael