I am having a serious issue. Our company has been bombarded by spam the last two weeks. Our return address is being spoofed and sending back tons of "Delivery Failure" notifications. Along with this, we are recieving an influx of other spam (like the outlook express update email) across all domains. Here is a copy of some of the headers
Received: (qmail 29800 invoked by uid 64021); 24 Jun 2009 13:43:16 -0000
Received: from 184.108.40.206 by mx1.swiftel.com.au (envelope-from <firstname.lastname@example.org>, uid 64011) with qmail-scanner-1.24
Processed in 1.183734 secs); 24 Jun 2009 13:43:16 -0000
Received: from unknown (HELO 18924121181.user.veloxzone.com.br) (220.127.116.11)
by mx1.swiftel.com.au with SMTP; 24 Jun 2009 13:43:15 -0000
Date: Wed, 24 Jun 2009 10:42:48 -0300
Subject: Want a BetterSex Life use AcaiBerry
Content-Type: text/html; charset="ISO-8859-1"
I have tried to implement Sender Policy Framework with our DNS host, but I'm not thinking it's working since the same emails are still getting through.
We are using a WatchGuard Firewall X700 and Mail Marshal as our spam filter.
Does anyone have any suggestions on ways to filter out more of this erroneous spam? Is anyone else experiencing large amounts of this spam as well?