Any mail server that hosts virtual servers will fail the verify HELO domain. Many may fail reverse DNS (over 1/2 of the servers I've informally looked at will fail that test - it's RFC but many don't properly follow it). Verify Mail From is very processor and bandwidth intensive and may improperly identify some valid sources. All in all - I avoided all three of those tests, after some careful experimentation.
Lee Drake -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Daniel Armstrong Sent: Wednesday, July 30, 2003 1:18 PM To: [EMAIL PROTECTED] Subject: RE: [IMail Forum] V8 Spam Filtering (Modified Question) Hello all, My question/contribution regarding this thread is a bit off the original topic, but this thread has brought to light some questions that we've been pondering. We are not using V8's connection filtering to test for... - Verify MAIL FROM Address - Perform reverse DNS lookup for connecting server - Verify HELO/EHLO Domain ...because we don't fully understand how they work (beyond the limited information in User Guide and Ipswitch KB). It's also a bit risky to test these settings because the only action is to delete the message after a specified number of failures. If we use all 3 of these tests (with no DNS Blacklists) and delete messages that fail 3 of 3, what scenarios are likely that legitimate e-mail will fail all 3 tests? Thanks, Daniel Armstrong > > From: "R. Scott Perry" <[EMAIL PROTECTED]> > > Organization: Computerized Horizons > > Reply-To: [EMAIL PROTECTED] > > Date: Wed, 30 Jul 2003 10:23:28 -0400 > > To: [EMAIL PROTECTED] > > Subject: Re: [IMail Forum] V8 Spam Filtering > > > > Actually, Declude JunkMail gets around this issue by only running the > test > > on non-local users. The idea is that since huge numbers of mail clients > > have invalid HELO/EHLO data, by only running the test on E-mails that > are > > sent from non-local users, it should normally only be running the test > on > > mailservers. > > I never noticed that before. I just looked at some samples. I guess I > meant > for all the tests. I wish that I could turn off all the spam tests if I > have > a SMTP Auth'd user. That I can't do in Declude right? > > -Josh > > > 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/ 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/ 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/
