[CentOS] sendmail / logwatch relaying issue - driving me crazy

Thu Dec 23 13:30:29 UTC 2010
Les Mikesell <lesmikesell at gmail.com>

On 12/23/10 3:44 AM, Götz Reinicke - IT-Koordinator wrote:
> Hallo, *<:-)
> may be I'm to tired to see the solution, maybe someone can give me a hint?
> I do have a couple of servers, sending the daily logwatch report to a
> central support email account.
> Some servers do have DNS A and CNAME records. On my mailserver relaying
> for the servers is allowed.
> Only one server drives me crazy, getting user unknown or releaying
> denied messages.
> Any idea, how to debug this issue? I'd be glad to fix this as a
> christmas gift. I could provide logmessages of course.

If there is an MX record for the target address, it will go there instead of to 
the A record for that name.   The receiving server will usually try to resolve 
the From: host address and reject if it can't, so the sender must have a valid 
hostname in your DNS (or turn off that feature).  If the receiving server 
doesn't accept for the target domain/host address you'd get the relaying denyed 
error.  If it does accept for the domain but does not have the user in the 
address you'd get the user unknown error.

   Les Mikesell
     lesmikesell at gmail.com