From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <20030709013624.15241.qmail@g.bio.cse.psu.edu>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] pop3 before smtp
In-reply-to: <016201c345b7$c60edb60$d2944251@insultant.net>
References: <3B9042CE-B1A7-11D7-A840-000393D34A62@orthanc.ab.ca> <016201c345b7$c60edb60$d2944251@insultant.net>
From: Scott Schwartz <schwartz@bio.cse.psu.edu>
Date: Tue,  8 Jul 2003 21:36:23 -0400
Topicbox-Message-UUID: efa6978a-eacb-11e9-9e20-41e7f4b1d025

> what has it got to do with POP?

The idea is that there's no good way to distinguish SMTP message
submission by authorized users from message relaying by unauthorized ones.
But POP does authenticate you as a local user, and it can remember
your IP address, and your mail server can assume that attempts at mail
relaying from that IP are actually attempts at mail submission and that
they should be allowed.  It's a popular kludge.  And you don't need it
if your SMTP server is willing to authenticate local users.