Filtering Email

[Doug Hardie]

I have a local mail server (postfix, dovecot LDA) that receives mail that is forwarded from my main account's mail server.  Virtually all mail is forwarded so the received from address is the same for all.  For a number of years we have used drive-by mail blocking on the main MTA.  Basically it sends a TEMP_FAIL to the first email from an unknown sender and then if they later retry, it is accepted.  This blocked over 90% of the spam a few years ago as spammers didn't bother to pay for retries.  However, the environment has changed and it appears that the spammer's MTAs now do retry so a lot of spam is getting through.

I am looking to be able to filter mail on the local MTA (either postfix or dovecot) so that I can have a table of IP addresses/names that if any appear in any Received header the email is filtered to the bit bucket.  It appears that is possible in dovecot pigeonhole (I am using that).  However, it is not table driven.  You have to write a rule for each name/IP.  I don't see anyway to have it refer to a table.  Is such possible?

— Doug