North American Network Operators Group
Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

Re: OT? /dev/null 5.1.1 email

  • From: Patrick Muldoon
  • Date: Tue Jul 05 22:50:47 2005 
Brad Knowles wrote:


At 4:00 PM -0400 2005-07-05, Jim Popovitch wrote:


 However, is seems the problem is over on the secondary MX (Postfix)
 which only has a list of legit relay domains for pMX.  When pMX is back
 online sMX fwds it's queue, but at that point pMX rejects to sMX...who
 then rejects to Sender.

Yup, and a lot of spammers take advantage of this fact by directly connecting to the secondary MXes of their targets, and never connecting to the primary MXes.

What about setting your highest order MX and lowest order MX to point to the same set of mail servers, and hide your backup servers in the middle. Even better if you can implement something that auto blacklists people that connect to your "secondary" MX's when you know that your primaries are up and accepting e-mail.

-Patrick