One small detail I left out - we don't run Imail on our 2 backup servers, so with this method Imail is not visible to the outside world. Traffic directed to our Imail server on Port 25 gets redirected to the Barracuda. Every single inbound email gets processed by the barracuda prior to delivery to Imail.
Our mail users use SSL, so we don't need to run on port 587. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Len Conrad Sent: Thursday, June 22, 2006 10:42 AM To: [email protected] Subject: RE: [IMail Forum] Junk Mail Bypassing Filtering >We have a Barracuda 300, and we handle this by passing off all email >through the cuda before it reaches the users' mailboxes. We have 3 >email servers, with only one hosting email accounts, and all three are at least dual homed. >1 interface on each goes to the WAN, and another connects to a >separate, private LAN. The cuda is also only on the private LAN. The >backup mail servers route all incoming mail through the private LAN to >the cuda, where it's filtered or handed off to the primary server and delivered to users. >If mail is sent from the Internet directly to the primary server, a >port redirector on that server redirects the traffic to cuda on the >private LAN, which in turn processes for spam and then passes back off >to the primary server via a different port number. > >It sounds a bit confusing, but it works like a charm for us. not a good approach, because attacks on Imail from internet flow thru Imail and back to the MX. Much better is this: activate port 587 on Imail, SMTP AUTH only. Submitters/roamers must submit to port 587. Firewall blocks internet access to imail port 25 (or redirect port 25 to 587). Len 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/
