Is usually listen on tcp 783 port. netstat -ntulpn is your friend to get open port list and program name:
Basically you force sendmail or postfix to send all mail through procmal , so there is no need to set up a ~/.forward file.
If you are using Postfix add following command to /etc/postfix/main.cf
Code:
mailbox_command = /usr/bin/procmail
Restart postfix.
Next in /etc/procmailrc you add something as follows.. which tells to filter everything through spamassassin:
Code:
# Send all mail through Spamassassin
:0 fw
* < 256000
| /usr/bin/spamc -f -u mail
Replace line with /usr/bin/spamc -f -u mail with actual path to spamassassin file.
That is all you need to do to get started with Spamassassin.