What to do with SpamAssassin after installing Amavis?

Question

As far as I know, Amavis has SpamAssassin on his own (I think Perl Mail::SpamAssassin).

Before installing Amavis, I was using SpamAssassin binary and daemon (spamc and spamd) plugged into MTA (Postfix via pipe).

My question is: what to do - is it safe to apt-get remove spamassassin now after installation and configuring of Amavis?

OS is Ubuntu 14.04 LTS.

Answer 1

According to Ubuntu 14.04 Server Guide Mail Filtering:

Amavisd-new is a wrapper program that can call any number of content filtering programs for spam detection, antivirus, etc.

You still need SpamAssassin, so you should not uninstall it. Actually, amavisd-new-postfix depends on spamassassin, so removing the package with apt-get remove spamassassin will also remove Amavis.

This chart visualizes how the pieces fit together (based on the same Mail Filtering guide):

You should

1. remove the pipe to SpamAssassin from your Postfix configuration, i.e. remove:

   smtp      inet  n      -      -      -      -      smtpd -o content_filter=spamfilter
   

   and

   spamassassin
        unix  -       n       n       -       -       pipe
        flags=R
        user=spamuser 
        argv=/usr/bin/spamc 
        -e /usr/sbin/sendmail 
        -oi -f ${sender} ${recipient}
   

2. integrate Amavis to Postfix, instead.

   For Postfix integration, enter the following from a terminal prompt:

   sudo postconf -e 'content_filter = smtp-amavis:[127.0.0.1]:10024'
   

   Next edit /etc/postfix/master.cf and add the following to the end of the file:

   smtp-amavis     unix    -       -       -       -       2       smtp
           -o smtp_data_done_timeout=1200
           -o smtp_send_xforward_command=yes
           -o disable_dns_lookups=yes
           -o max_use=20
   
   127.0.0.1:10025 inet    n       -       -       -       -       smtpd
           -o content_filter=
           -o local_recipient_maps=
           -o relay_recipient_maps=
           -o smtpd_restriction_classes=
           -o smtpd_delay_reject=no
           -o smtpd_client_restrictions=permit_mynetworks,reject
           -o smtpd_helo_restrictions=
           -o smtpd_sender_restrictions=
           -o smtpd_recipient_restrictions=permit_mynetworks,reject
           -o smtpd_data_restrictions=reject_unauth_pipelining
           -o smtpd_end_of_data_restrictions=
           -o mynetworks=127.0.0.0/8
           -o smtpd_error_sleep_time=0
           -o smtpd_soft_error_limit=1001
           -o smtpd_hard_error_limit=1000
           -o smtpd_client_connection_count_limit=0
           -o smtpd_client_connection_rate_limit=0
           -o receive_override_options=no_header_body_checks,no_unknown_recipient_checks,no_milters
   

   Also add the following two lines immediately below the "pickup" transport service:

    -o content_filter=
    -o receive_override_options=no_header_body_checks