[GRLUG] Sendmail as secondary (backup) MX

[Benjamin Eavey]

This would work if I were in control of the other mail servers, but I'm 
not.  I'm just acting as a backup in case the other servers are down, to 
make sure mail will be queued up.  The other mail servers have their own 
admins who don't communicate with me when they add and remove users.

It's sounds like I have things set up "correctly" -- it's just that 
doing things correctly, in this case, is kinda crappy.

So there's no way for my server to simply drop any undeliverable 
messages it receives from the servers it's backing up?  It's pretty safe 
to say that any undeliverables are probably spam.

It feels messy.  Any more advice, from anyone?

Thanks,
-Ben


Chris Lamrock wrote:
> Hey Ben -
> 
> You should be able to set up a primary MX server and use it as a gateway to 
> your main mail server.
> I have a similar configuration here however my primary MX server runs DSPAM 
> and postfix which
> forwards the "good" emails to my email server running sendmail.  Of course I 
> also use DSPAM
> for our anti-spam protection - but I'm sure you could set up postfix to 
> check a virtuser table and then
> forward or not...    By the way - DSPAM works good for us...
> 
> 
> -Chris
> 
> 
> ----- Original Message ----- 
> From: "Benjamin Eavey" <ben at eavey.com>
> To: <grlug at grlug.org>
> Sent: Tuesday, October 31, 2006 10:36 AM
> Subject: [GRLUG] Sendmail as secondary (backup) MX
> 
> 
>> Has anyone set this up and worked out all the kinks?  I have a machine
>> running Sendmail and acting as a backup MX for several domains.
>> Everything has been working fine, for the most part, but now I'm running
>> into problems with the queue becoming overloaded.
>>
>> It looks like a bunch of spam, and it appears to be a bunch of "550 -
>> undeliverable" messages and other similar stuff.  Looks like the
>> spammers are sending to non-existent addresses at the domains I host,
>> which are then bouncing with "undeliverable" messages, which are then
>> building up on my sendmail server, which is trying to deliver them to
>> the spoofed originating email addresses.
>>
>> I know this is bad, and I'm pulling my hair trying to figure out how to
>> make this work properly, but I'm not getting anywhere.
>>
>> Can anyone offer any suggestions?  Am I explaining this well enough that
>> the problem makes sense?
>>
>> Thanks,
>>
>> -Ben