Hi, I am fairly new to the email environment (at least to the administration of it). I have recently inherited an email system that has developed a somewhat unfavourable reputation with some of the anti-spam sites. I have been trying to address this through the use of spamassassin and amavis with some success. Success in the sense that spam is no longer entering our system. However it is still being passed through.
My first question is how do I configure postfix to send all outgoing mail through amavis? We can police this to some extent by identifying the users who are originating the spam and adding them to a blacklist. But our problem is confounded by the large numer of 3G and GPRS users that we support. Many of these simply use our smtp server as an 'open relay' to braodcast mail. Our server is not really 'open' in that only user with 3G/GPRS accounts can access it, but it is extremely difficult to identify the source of the connection in real time. What I really want to do is perform spam filtering on all mail that passes through our relay, this will allow us to keep life simple for users (no authentication beyond having a valid 3G/GPRS account) and yet prevent us from polluting the internet with spam. I am sure that it is possible to configure postfix to do this and that it is just my lack of experience in this field that is preventing me from seeing ths solution. Any pointers/tips/etc. gratefully considered. TIA mike
