Would be very useful to have an iMail server only accept incoming SMTP connections that are authenticated and reject all others.
In our case, we are using store and forward configuration with two mail servers. We have an incoming server that is the target of the MX to receive all regular incoming mail and then forward to the iMAIL mailbox server which only runs pop/imap/webmail. Users with their email hosted on our servers must set their pop/imap configuration to our mailbox server so they can authenticate and send from their own isp. (This is a very small percentage of the total incoming traffic so we don't mind having it coming directly into the mailbox server.) Unfortunately, some spammers look up the DNS and instead of using the MX record they try the alternate host records such as "mail" or "pop" which point to our mailbox server and then try to connect to deliver their spam. If we could set iMail to only allow incoming authenticated sessions, it would block these connections. We can't use IP addresses because we don't know the IP's of our clients and it varies. Is there any port forwarding utility that can sniff packets and block non-authentication sessions or is there any other solution than waiting for imail to have an "accept only authenticated smtp connections" option? -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Darin Cox Sent: Monday, August 02, 2004 2:30 PM To: [EMAIL PROTECTED] Subject: Re: [IMail Forum] BellSouth now blocking port 25 Gotcha...I'll look it up. Thanks, Scott. Darin. ----- Original Message ----- From: "R. Scott Perry" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Monday, August 02, 2004 4:20 PM Subject: Re: [IMail Forum] BellSouth now blocking port 25 >Migrating to port 587 for AUTH doesn't really seem useful. Unless there is >an end goal of separating MTA -> MTA traffic from MUA -> MTA traffic, it >seems to me that SMTP AUTH should be used everywhere on port 25...no need to >move everything to a separate port except due to ISPs who choose to shut >down port 25 usage except to their servers. It isn't due to ISPs shutting down port 25. There is an end goal of separating the two types of traffic. See RFC2476 for details. It was written in 1998, but one of the reasons was to help stop spam. -Scott --- 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/
