[Pkg-exim4-users] After upgrading to exim4 messages are frozen, "remote host address is the local host"

[Matthew Exon]

Hi,

I'm running Debian unstable, and I decided I wanted to upgrade to exim4. 
  When I did so, I found that all mail, both from on the host itself and 
from the wider internet, wasn't being delivered any more.  A typical 
message (this one happened to be a test mail I sent to myself on the 
server machine itself) produces this log file:

2005-03-07 11:00:05 Received from <username>@exon.dyndns.org 
U=<username> P=local S=335
2005-03-07 11:00:05 <username>@exon.dyndns.org R=dnslookup defer (-1): 
remote host address is the local host
*** Frozen

When I asked about this on the exim support list, I was told that I must 
have misconfigured my machine's local mail domains.  I don't really 
understand that, but it sounds like the debconf question that asked me 
which domains should be considered local.  I entered "exon.dyndns.org" 
and another host, "aeon.exon.dyndns.org", as local domains, so that 
sounds right to me.  I'm at a loss what else I've done wrong.

However, this talk of DNS lookups does remind me that there's weird 
behaviour on my machine, in that all invalid domains seem to resolve to 
my own machine:

charly:~# ping blah.org
PING exon.dyndns.org (82.135.65.152): 56 data bytes
64 bytes from 82.135.65.152: icmp_seq=0 ttl=64 time=0.9 ms

I've never understood why that happens, or even been sure it wasn't a 
"feature".  So possibly it's the DNS or IP masquerading systems that are 
at fault.  But still, at least local mail delivery should be immune to 
that, right?

I don't really want to be playing with all this stuff - I'm just trying 
to work around bugs in Thunderbird.  Thunderbird doesn't play nicely 
with mbox servers - you can't create folders with subfolders if you ever 
want to delete them again later.  And mbox doesn't support folders which 
contain both messages and subfolders.

So I'm trying to migrate to maildir.  But that doesn't seem to be 
trivial under Debian, and if I'm going to get any support from the exim 
mailing list, I'm told I need to be on exim4.  Hence the upgrade.

I just went a day without receiving any email, which I've fixed by 
reverting to exim 3.  I don't really want to try the upgrade again 
unless I'm sure it's going to work...

Any advice?

Thanks,
Matthew Exon