Try learning about SpamAssassin's notfirsthop DNS blacklist option, and why it might be a sensible idea, you utter cretins.
This message was created automatically by mail delivery software. A message that you sent could not be delivered to one or more of its recipients. This is a permanent error. The following address(es) failed: zzzzzzzz@pts.edu SMTP error from remote mail server after end of data: host smtp.pts.edu [72.22.0.101]: 554 Service unavailable; Client host [ppsw-5.csi.cam.ac.uk] blocked using Barracuda Reputation; http://bbl.barracudacentral.com/q.cgi?ip=86.165.170.59 ------ This is a copy of the message, including all the headers. ------ Return-path:X-Cam-SpamDetails: Not scanned X-Cam-AntiVirus: No virus found X-Cam-ScannerInfo: http://www.cam.ac.uk/cs/email/scanner/ Received: from [86.165.170.59] (port=51166 helo=[192.168.1.2]) by ppsw-5.csi.cam.ac.uk (smtp.hermes.cam.ac.uk [131.111.8.155]:587) with esmtpsa (PLAIN:zzz99) (TLSv1:AES128-SHA:128) id 1JHf30-0003CD-Il (Exim 4.67) (return-path ); Wed, 23 Jan 2008 12:49:42 +0000 Mime-Version: 1.0 (Apple Message framework v752.3) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed ...