Filtering Spam with Spamassassin on Redhat 9
                                                                                
Keywords: Redhat Spamassassin Procmail Sendmail Fetchmail Spam Hotwayd
                                                                                
                                                                                

SPAM had finally gotten to the point in my life that I could stand it no more.

Before I was just a little annoyed and sometimes mildly amused by various offers for septic tanks and promises of an enlarged male organ. I have several email accounts, each of which receive a few unsolicited messages per day. I end up with about 100 spams a week and growing, so decided it was time to find a way to filter those bastards to /dev/null once and for all.

Here's a brief rundown of what I'm doing followed by the configuration.
                                                                                

1. Mail is grabbed from various accounts using Fetchmail. I also use Hotwayd to POP my hotmail as I phase out this godforsaken service.

2. Procmail forwards messages to Spamassasin for analysis.

3. The subject line gets labelled with [SPAM] if it is considered to be spam.

3. Procmail gets back the message and drops it where it's been told to be put (mine goes to /dev/null).

4. From there I can use the mail reader of my choice to read my virtually spam free messages.

                                                                                

Getting Spamassassin to work.

Sendmail, Procmail, Spamassassin, and Fetchmail are all included in the RH9 distribution, but you may need to install some of them manually. If you prefer Postfix over Sendmail, it's up to you. Make sure they are all installed before getting started. You should also make sure your sendmail is working by sending yourself a test message. From the command line you can type:

Verify your mail is working first.

mail -s TEST username (where username is the username you're logged in as) This is a test <ctrl + d>

If you then type "mail" and hit enter, you should see your message. If not, you've got to get your mail working which is beyond the scope of this article.

Procmail

By default, Sendmail should be configured to send all mail through Procmail, so there is no need to set up a ~/.forward file.  To verify, you can check your /etc/mail/sendmail.rf.  You should see an entry like: FEATURE(local_procmail,`',`procmail -t -Y -a $h -d $u')dnl.

Next, create /etc/procmailrc if it does not exist (it shouldn't if you are working with a new install of RH9).  Make sure you've got the following lines.

DROPPRIVS=yes #Uncomment the following lines to allow for logging # #LOGFILE=/var/log/procmail #VERBOSE=ON :0fw # The following line tells Procmail to send messages to Spamassassin only if they are less thatn 256000 bytes. Most spam falls well below this size and a larger size could seriously affect performance.) * < 256000 | /usr/bin/spamassassin -P :0e { EXITCODE=$? }

That is all you need to do to get started.  All mail delivered to your local mailbox will have [spam] added to the subject.  You can use your favorite mail reader to filter as you wish, or if you want Procmail to move it somewhere, create or edit your ~/.procmailrc file and add the following lines.

:0: * ^X-Spam-Status: Yes /home/username/mail/spam

You can configure the last line to put marked messages wherever you want. If you change the line to /dev/null you will immediately get rid of spam. Make sure to test out Spamassassin for a while before deciding to do so, though.

Fetchmail