What about a mail proxy server gateway placed in front of imail that would automatically block any incomming connection containing words such as "dsl" and "cable" in their reverse DNS or IP, if no attempt was made to authenticate via SMTP AUTH?
There's someone that already has such a gizmo.
The problem is that many small businesses use business class DSL or cable connections that do not have customizeable reverse DNS entries. One person originally claimed to have good results -- but after further testing, they were blocking about 10-15% of legitimate E-mail.
Our philosophy has always been that you should never block an E-mail based on any one test. Even if only 1% of legitimate E-mails come from mailservers using dsl/cable, that would still result in a minimum false positive ratio of 1%. Multiply that by perhaps 10 different spam tests, and you have quite a few false positives.
-Scott
---
Declude JunkMail: The advanced anti-spam solution for IMail mailservers since 2000.
Declude Virus: Ultra reliable virus detection and the leader in mailserver vulnerability detection.
Find out what you've been missing: Ask for a free 30-day evaluation.
---- This outgoing message is guaranteed to be authentic by Message Level users. Guarantee the authenticity of your email @ http://www.messagelevel.com. --- [This E-mail was scanned for viruses by Declude Virus (http://www.declude.com)]
To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
