I think i JUST found my solution (after 30 minutes of looking over everything). It always seems you find your help, just after you post the question!
the line was in the /etc/postfix/main.cf, and it was 'content_filter = amavis:[127.0.0.1]:10024'
NOw... that was pretty simple... yes?!
Thanks anyway! I hope that this was in fact what I screwed up.