[ale] Filtering mail

Jacob Langseth jlangseth at esisys.com
Fri Nov 7 14:06:18 EST 1997


On Friday, November 07, 1997 2:39 PM, chrisf at computone.com 
[SMTP:chrisf at computone.com] wrote:
> I want to send all mail through a BASH filter that will look for certain 
words
> and content.  I know I can do this in the alias file for each individual 
user,
> but I with there was one global place I could put it then if the mail passes
> inspection, it can go to the person it belongs to.

Sounds kinda big-brotherish.... ;-)  Hopefully you have a good,
ethical reason for doing so.

Before anyone can answer your question, they'll need to know
what mailer your using (qmail, sendmail, smail, etc).  Most can
be configured to use a specific program for delivering mail locally;
sendmail, for instance, can be configured to use procmail.  If you
set your site up thusly, it would (I believe) just be a matter of
placing the appropriate rules in the global procmailrc to handle
the filter...

What would be nice, imo, is a security filter on _outbound_ mail,
such that the administrator gets a warning message if someone
mails off messages matching a defined pattern...  It would be
trivial to bypass locally (connect to port 25 and send the mail
manually), but might be the critical alarm bell if someone mails
off /etc/shadow using some new remote exploit...  Probably
have to wrap /bin/mail.  Anyone know off the top of their head if
mailers (smail in my case) support outboud filtering?
hmmm...

--
Jacob Langseth			Enhanced Systems, Inc.
CTI Engineer			Email for PGP key
<jlangseth at esisys.com>		#include <std_disclaimer.h>






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