sal-wrapper.pl: configuration examples

In the following sections you will find some examples about how to use sal-wrapper.pl

How to use it with postfix (top)

In the following I will describe how to use sal-wrapper.pl with postfix. This setup is mainly, but not only, used on a mail gateway. This will only work if you have just one user which runs your spamassassin and which scans all passing emails.

Download sal-wrapper.pl and store it somewhere (/path/to/sal-wrapper.pl)

• You need two accounts on your mailserver: »spam« and »ham«. You can realize this by adding the following lines to your alias (default: /etc/aliases) file:

  ham:    postmaster
  spam:   postmaster

• Add the following two lines to your master.cf (default: /etc/postfix/master.cf) file:

  sa-wrapper unix   -     n    n     -     -     pipe
  user=vscan   argv=/path/to/sal-wrapper.pl --${mailbox}

  replace the user »vscan« with the user which runs your spamassassin and replace '/path/to/sal-wrapper.pl' with the path to the script. If you use spamc as your learning client, then replace --${mailbox} with -L ${mailbox}. Restart postfix.

• Enable the use of a transport table by specifing the following in your main.cf file:

  transport_maps = hash:/etc/postfix/transport

  And add the following to your transport table:

  spam@your.server.tld    sa-wrapper:
  ham@your.server.tld     sa-wrapper:

  Then don't forget to rebuild the map with postmap transport.

• Create the needed logfile and directory:

  touch /var/log/sa-learn.log
  chown vscan:log /var/log/sa-learn.log
  chmod 644 /var/log/sa-learn.log
  mkdir /var/spool/unpack
  chown root:vscan /var/spool/unpack
  chmod 774 /var/spool/unpack

• Edit spamassassin's local.cf file (default: /etc/mail/spamassassin/local.cf) and activate bayes.

  use_bayes 1
use_bayes_rules 1
bayes_auto_learn 1

• It may be worth to use a restriction table in Postfix to prevent outside MTAs to deliver mails to the »spam« and »ham« accounts. The sal-wrapper Script is by itself capable to discard mails from outside, so the following step is not absolutly necessary.

  The the below given code shows an example of how to change the recipient restrictions in Postfix's main.cf to reject mails from outside to the »spam« or »ham« addresses:

  smtpd_recipient_restrictions =
  ...
  permit_mynetworks
  permit_sasl_authenticated    # only if you use sasl
  check_recipient_access hash:/etc/postfix/recipient_access.outside
  ...


  Create the file /etc/postfix/recipient_access.outside and add this content:

    spam@your.server.tld     REJECT 5.2.1 recipient unavailable from outside
    ham@your.server.tld      REJECT 5.2.1 recipient unavailable from outside

  Don't forget to execute: postmap /etc/postfix/recipient_access.outside

Now you can put your spam messages in the appendix of a new mail and send it to spam@your.server.tld. The same with your ham mails, put them in the appendix of a new message and send it to ham@your.server.tld.

How to use it with Postfix (alternative) (top)

This alternative method uses a second aliases map to run the sal-wrapper script. Create a new aliases map whose owner is the user which runs spamassassin.

Download sal-wrapper.pl and store it somewhere (/path/to/sal-wrapper.pl)

• Then create a new aliases file and change the user (this ist important because the commands in the aliases file will run with the privileges of the file owner).

  # touch /etc/report_aliases
  # chown YOUR_USER /etc/report_aliases

• Then add the following content to the new aliases map. If you use spamc as your learning client, then replace --${mailbox} with -L ${mailbox}.

  spam: "|/PATH/TO/sal-wrapper.pl --spam"
  ham:  "|/PATH/TO/sal-wrapper.pl --ham"
  

• Then add the report_aliases map to alias_maps in main.cf:

  ...
  alias_maps = hash:/etc/aliases, hash:/etc/report_aliases
  ...
  

• Create the new aliases database and reload Postfix:

  # postalias /etc/report_aliases
  # /sbin/rcpostfix reload
  

• Prevent outside clients to send messages to your »spam« and »ham« accounts. See: add a restriction table

Finally you can send messages to ham@your.server.tld and spam@your.server.tld to learn them as ham or spam.

How to use it with procmail (top)

Unfortunately I don't use procmail by my self, so I just copied the procmail.rc script from huschi.net. This will be useful if you run SpamAssassin on a per user basis and if you have the user accounts locally on your server.

~/procmail.rc:

VERBOSE=ON
LOGFILE=/var/log/procmail.log

:0
* ^To: spam@your.server.tld
{
:0fw
| /usr/local/bin/sa-wrap.pl --spam
:0
/dev/null
}

:0
* ^To: ham@your.server.tld
{
:0fw
| /usr/local/bin/sa-wrap.pl --ham
:0
/dev/null

If you use spamc as your learning client, then replace --${mailbox} with -L ${mailbox}.