From mboxrd@z Thu Jan  1 00:00:00 1970
Date: Mon, 30 Nov 1998 18:02:43 -0500
From: Russ Cox rsc@eecs.harvard.edu
Subject: [9fans] pop3 client
Topicbox-Message-UUID: 8bd4c45a-eac8-11e9-9e20-41e7f4b1d025
Message-ID: <19981130230243.kHmAcaBAH6ou7_2Gna_9fXRBORLnnkG7yi_J75rKnis@z>

There's a pop3 client I wrote and used for a while a year ago
at http://plan9.bell-labs.com/~rsc/pop3get.c

It's somewhat rough, but if you're willing to spend a little
time hacking at it it's probably fairly usable.

The invocation was something like
	pop3get -drN maxsize -s secretfile server 

-d deletes the messages when done.  if you don't delete, you'll
get the same messages next time.

-r reads the mail box in reverse order; you won't need this flag.
-N max sets a maximum message size to download. 
-s secretfile reads a password from file.

pop3get downloads the mail and then runs upas/sendmail to
deliver it to the local user.

There are references to MD5 routines from a non-existant
<libcrypt.h> to do challenge-response authentication.
If all you want is password, just comment out the MD5 calls and
specify the -p flag to use plaintext passwords.
If you want challenge-response, you can probably pull the
appropriate MD5 code from /sys/src/cmd/md5sum.c

Finally, you'll see that the sendmail call calls
upas/mysendmail and not upas/sendmail.
I think the difference was that mysendmail pulled
the sender from the From: line if there was no
Unix-style From line; that was some bit of ugliness
I never got around.  I don't remember.

Like I said, it's a little rough in places, but it's a start.
I'ld be interested in any changes.

An alternative place to look would be Eric Raymond's fetchmail,
which does a functionally similar thing; I don't know how hard
it would be to port to Plan 9.  It delivers the mail by connecting
to port 25 of the local machine, so you'ld need to be running
smtpd, and you'ld need David Butler's loopback device to get 127.0.0.1.

Russ