RE: fix.your.open.relay.or.die.net -- MIDRANGE-L

James,

That is NOT possible. How does you server know "you" are you and not me
pretending to be you? There must be something enabled. Perhaps something
that says you must check for new mail before sending old mail? Many servers
assume you're allowed to relay IF the IP your sending from has checked for
new mail in the last several minutes. Since checking for new mail requires a
userid and password they can safely assume you're authorized. The
check-before-send is NOT part of the RFC, but may be a default config for
sendmail.  Otherwise what's to stop me from configuring a copy of netscape
like you just described and SPAMing the world?

-Walden

------------
Walden H Leverich III
President
Tech Software
(516)627-3800 x11
WaldenL@TechSoftInc.com
http://www.TechSoftInc.com



-----Original Message-----
From: James Rich [mailto:james@eaerich.com]
Sent: Wednesday, November 21, 2001 5:40 PM
To: 'midrange-l@midrange.com'
Subject: RE: fix.your.open.relay.or.die.net


Let's lay this thing to bed.  You *can* deny open relaying *and* allow your
remote users to send you email from anywhere *and* read their email from
anywhere.  I wanted to be sure I had things right before posting.

Open relays are not necessary for proper SMTP function.  You don't need
non-standard firewalls or non-standard software.  While the details of my
configuration are off topic for this list (since I don't use OS/400 for
anything mail-related), a general outline will help so that we can discover
if the same will work on OS/400.

For me, "standard" is:

server: sendmail-8.11 (running on whatever, linux in this case)
client: mozilla-0.9.6 (or any other netscape mail client)

I tested my email server through two different relaying testers to be sure
that open relaying was disabled.  I configured mozilla with my name, etc.
and put my server in the outgoing SMTP box.  I then connected from home
using whatever ip address my ISP gave me.  My email server has no special
rules regarding ip addresses or forwarding.  I sent an email message from
home to somewhere not in the domain of my email server.  It was sent just
fine.

So open relays are not needed and are rightfully frowned upon.  I don't know
how to do any of the above on OS/400 but it ought to work.

James Rich
james@eaerich.com

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