A few months ago, I upgraded my mail transport servers to opensuse 12.2. In the recent couple of weeks, I've been recieving a large number of spam in my emails which has never been the case. The configuration files have not changed, amavis is still scanning for viruses using camav. So what's different?
It turns out that since the new version of amavis, it no longer sends email to spamassassin for processing unless the email is destined for one of the local domains. This actually makes sense, especially if the MTA will relay non-local domain emails.
To fix this, just add your local domains to @local_domains_maps in /etc/amavisd.conf:
@local_domains_maps = ( [".$mydomain", "myotherdomain.com", "exampledomain.com"] );
Reload amavisd configuration and you should be good as new.