E-mail configurations

Summary

The MTA (mail transport agent) is needed to send mail from the box -- you don't need anything to receive mail, unless the box acts as a mail server (which is a security risk).  Exim or procmail are commonly used and should work out of the box.

GnuPG is a free version of PGP for mail encryption and secure communication. It's set up for Thunderbird on clitunno.

Installation history

steen@clitunno:~/mail$ ln -sf /share/data/ImapMail/LocalFolders/Teaching.sbd/2007.sbd/128 128

I've set the local folders for Thunderbird to sigillo:/spare/ImapMail and clitunno:/share/data/ImapMail -- normally, I expect to be using clitunno for e-mail, but if you plan to travel do a sync from clitunno to sigillo.

GnuPG
5 December 2004 on clitunno

• Using the GNU Privacy Guard
• How to secure your e-mails with GnuPG and Enigmail (most up to date)
  
• Encrypting your e-mails with Thunderbird, Enigmail & GnuPG
• Debian
  
• gnupg
  
• mozilla-thunderbird-enigmail
  
• kgpg (for managing keys)
  

gpg --keyserver wwwkeys.pgp.net --send-keys 0x<public key ID>

Exim (I put a copy of this section in Sigillo/exim.html)
18 January 2004 on sigillo

• exim

So every 15 minutes this mail command runs. I don't see where the command is given -- kcron or crontab -e doesn't show it. There is a /etc/init.d/exim file -- but exim may also be running from /etc/inetd.conf. In fact I have this line there:

#:MAIL: Mail, news and uucp services.
smtp            stream  tcp     nowait  mail    /usr/sbin/exim exim -bs

When I issue "just list-files exim" I get (among other things) this:

/etc/init.d/exim
/etc/cron.daily/exim
/etc/cron.d/exim

So that's where it's started. The /etc/cron.daily/exim "cycles logs" -- dumps the old log to /dev/null. The /etc/cron.d/exim has the rest:

# /etc/cron.d/exim: crontab fragment for exim

# Run queue every 15 minutes
08,23,38,53 *     * * *     mail   if [ -x /usr/lib/exim/exim3 -a -f /etc/exim/exim.conf ]; then /usr/lib/exim/exim3 -q ; fi

# Tidy databases
13 6 * * *      mail    if [ -x /usr/sbin/exim_tidydb ]; then /usr/sbin/exim_tidydb /var/spool/exim retry >/dev/null; fi
17 6 * * *      mail    if [ -x /usr/sbin/exim_tidydb ]; then /usr/sbin/exim_tidydb /var/spool/exim wait-remote_smtp >/dev/null; fi

Procmail

See the working promail on weber for an example, or this article.

On 7 August 2002 I complained to DigitalSpace.net's Wonderdesk that I was getting spoofed. He said they can't do anything, but that I could use procmail filtering.

There's a full list of procmail filtering scripts at
http://www.ling.helsinki.fi/users/reriksso/procmail/links.html#antispam

Here's a thorough one: http://www.spambouncer.org/

And one more: http://junkfilter.zer0.org/

I found instructions at http://www.css.tayloru.edu/~bbell/spam-filter/ for a simple setup (I hoped) and verified with a "locate procmail" that I had it, in /usr/bin/procmail.

Modeled on his, I created this .forward file:
"|IFS=' ' && exec /usr/bin/procmail -f- || exit 75 #cogweb"

I got trouble -- this blocks all mail. I tried removing the -f- but it made no difference.

I found better instructions here:
http://www.uwasa.fi/~ts/info/spamfoil.html

I did a supersimple setup on /home/cogweb, but it just blocks all incoming
mail. I asked support for help.

I have several mail accounts with the frog people. My root directory:

/home/cogweb

First priority is steen: cd /home/mail/steen. However, I don't have write access in this directory. I'll try installing things on /home/cogweb and see if that catches the mail to steen (unlikely).

Then I issued this elegant little command:

wget http://www.css.tayloru.edu/~bbell/spam-filter/.procmailrc

and the file was in place! So I have quite a bit of power on this machine.

I then created the .procmail directory under /home/cogweb. I tested that $HOME was what it should be with a echo $HOME and got /home/cogweb.

I then downloaded rc.maillists, which lists acceptable From: before the filter kicks in. Again I did it by wget http://www.css.tayloru.edu/~bbell/spam-filter/rc.maillists and then mv rc.maillists .procmail

Here's rc.maillists, unmodified:

# For this mailing list, just treat it as a normal file

:0
* From.*HumourNet
$DEFAULT

# This mailing list is HTML based, and I normally us a text-based
# mail reader, so forward all mail to another account I have
:0
* From.*infobeat.com
!other-acct@some-isp.com

# All mail from this list goes into the specified folder. This should
work
# with pine, elm, and other Un*x mail readers, but will not work when
# checking mail from Windows (using a POP3 client).
:0
* From.*javasoft.com
INBOX.java

"For more information on procmail recipes, see examples under the procmailrc and procmailex man pages."

Next, the spam filter. See the full explanation here:
http://www.css.tayloru.edu/~bbell/spam-filter/rc.spam.html

I got it with wget http://www.css.tayloru.edu/~bbell/spam-filter/rc.spam
and moved it to .procmail.

He assumes the following, now dubious:

To verify that the message is spam, I check to see if the message is not addressed to me. Rarely does a spam message actually list the real e-mail address in the "To" or "CC" field. Here I check to see if the message is (not) addressed to "bell". The reason is that I have a number of e-mail address that forward to this one account, but all have the word "bell" (my last name) in them. Replace "bell" with part or all of your e-mail address.

Here's the rc.spam, unmodified:

# First, catch any spam correction messages
:0
* ^Subject.*spam error
$DEFAULT

# Second, stop bounced messages
:0
* ^From: Mail Delivery Subsystem
{
:0 B
* X-Mailer: Bob's Spam Canceller
/dev/null
}

# Finally, nail those spammers!
:0
* !((^TO_.*taylor)|(^TO_.*bell))

| ~bbell/local/bin/formail -rf -I "X-Mailer: Bob's Spam Canceller" -I
"From: Bob Bell" -i "Subject: Your message has been deleted" | cat -
~bbell/.spam-msg | sendmail -t

I made these modifications: