warning: database /etc/aliases.db is older than source file /etc/aliases

run

newaliases

WARN: bayes: database version  is different than we understand (3), aborting!’ in logs.

use mysql query

insert into spamassassin.bayes_global_vars (variable, value) VALUES ("VERSION", 3);Jan 18 08:40:17 server amavis[25863]: (25863-01) (!!)ClamAV-clamd 

* * *

info: config: failed to parse line, skipping, in "/etc/spamassassin/local.cf": use_dcc 0

add

loadplugin Mail::SpamAssassin::Plugin::DCC

to to /etc/spamassassin/local.cf before use_dcc

av-scanner FAILED: run_av error: Too many retries to talk to /var/run/clamav/clamd.ctl 
(Can't connect to UNIX socket /var/run/clamav/clamd.ctl: Connection refused) at (eval 89) line 309.

clamav package is not enough. If you need clamd, you may also want to run

apt-get install clamav-daemon

* * *

ClamAV-clamd av-scanner FAILED: CODE(0x10fc620) unexpected ,  lstat() failed: Permission denied. ERROR\n" at (eval 111) line 899.

Add clamav user to the amavis group.

sudo usermod -a -G amavis clamav

and then restart the clamav and amavis daemons.

service clamav-daemon restart
service amavis restart