[ale] Monitoring outgoing emails on Postfix, filtering incoming bounce back messages

[Jim Popovitch]

On Mon, 2007-06-25 at 23:33 -0400, Jay Loden wrote:
> Problem is they're not undeliverable emails, someone is just spoofing
> my email address as the sender on a bunch of spams, so I'm getting
> hundreds of "unable to deliver message" responses from people's mail
> servers, e.g. postmaster at example.com or MAILER-DAEMON at example.com

Yep.  Happens all the time.  The first step to recovery is to admit to
yourself that you are powerless to fix it. ;-)

> It's frustrating because I don't know what else I can do short of
> filtering the messages by content. I wish there was a way to set it up
> so that bounce messages are only delivered if you actually sent a
> corresponding email in the first place. Stupid forged headers!

There are some ways to stem the tide.  Are you accepting inbound email
from everywhere, or just from valid systems that have matching PTR and A
records?  100% of blow-back that comes into my systems is dropped due to
not accepting email from unknown hosts (a ton of Corp mail scanners
thankfully don't have PTR records), or from rejection due to unknown
recipient.  YMMV.

-Jim P.