I have an exchange 2010 multi-tenant email server that has email addresses of many domains. I want to setup a spam filter for my mail server I have been looking on the internet but cant figure out the best solution to implement. Spamassasin with Postfix. Spamassasin i understand does not delete any emails but just marks the email. Postfix can be used as a MTA to forward email to the mail server. but postfix does not store any emails. how can i implement a solution whereby i have a server that stores all ham and spam emails but only forwards the ham emails to my mail server so i can check the spam server if there is any false positives. If you could please just give pointers in the right direction
thanks
Rehan Miah
Just set up spamassassin to mark all of the likely spam emails (set the score pretty high on day 1) and then set a Transport Rule on Exchange that intercepts the spams based on the string added to the subject field, and then does something with them (delete them, drop them in a spam trap mailbox, whatever).
Have the spamassassin box be the MX for the domains and then forward to the Exchange server (have the Exchange consider it a trusted sender) but make sure to lock spamassassin down to only allow mails sent to domains you care about.
If you have multiple domains, set up a test domain to try the spamassassin setup on before getting serious with clients' domains.