Amavis
From Amavis's site:
- amavisd-new is a high-performance interface between mailer (MTA) and content checkers: virus scanners, and/or SpamAssassin. It is written in Perl for maintainability, without paying a significant price for speed. It talks to MTA via (E)SMTP or LMTP, or by using helper programs. Best with Postfix, fine with dual-sendmail setup and Exim v4, works with sendmail/milter, or with any MTA as a SMTP relay.
Installation and setup
In this setup it is assumed that you are using ClamAV as anti-virus scanner.
- Install amavisd-new. You would be wise to also install optdepends such as p7zip and unrar so your filters can actually see inside compressed files.
- Install clamav.
Basic configuration
If your hostname is not a FQDN, you must set and $mydomain accordingly in /etc/amavisd/amavisd.conf.
You can enable ClamAV support by commenting out the following lines (do not forget to put the same as in ):
Add a comment to this line to enable anti-virus scan:
# @bypass_virus_check_maps = (1); # controls running of anti-virus code
After that, add clamav user to amavis group to avoid permission problems:
# usermod -a -G amavis clamav
Finally restart the services:
Check for errors with these commands:
# systemctl status amavisd # journalctl -u amavisd
Testing
To test the new configuration just telnet to the amavisd default listening port:
$ telnet 127.0.0.1 10024
You should see something like:
Type :
Now just type to exit.
Integration with Postfix
Quick start
To configure amavis for Postfix add the following to :
In this configuration we assume that postfix and Amavis are running on the same machine (i.e. 127.0.0.1). If that is not the case edit /etc/amavisd/amavisd.conf and the prevous Postfix entry accordingly.
Postfix will listen to port so that Amavis can send back checked emails to that port.
You also have to add another other configuration in your smtp or sections:
-o content_filter=amavisfeed:[127.0.0.1]:10024
Using this options implies that Postfix will send emails to Amavis on port , so that these can be checked. If mail passes the control then these are sent to port , as explained before.
We can now restart and .
To check that Postfix is listening on port do the same operations as the port case.
SpamAssassin support
Install
Spamassassin is integrated in Amavis so you do not have to start . To enable support for Spamassassin comment the following line in like this:
# @bypass_spam_checks_maps = (1); # controls running of anti-spam code
Edit the SpamAssassin configuration based on your needs:
Before you restart the amavisd service, run .
Final test
To check that everything is working as intended:
- Send a normal email.
- Send an email with an EICAR test file as attachment.
- Send an email that would result as spam.
- Check both Postfix and Amavis logs.