I am running a spam filter on debian lenny 5.1 with postfix, amavis-new, spamassassin, and clamav. It works pretty well but I would like to finish tweaking it to minimize the mail getting quarantined. It really isn't quarantining anything that isn't spam, except for an occasional list mailer. However, the quarantine is huge, and takes a while to go through. I noticed that much of the spam is coming from foreign country tld's like .cz is there anyway to have postfix run a check on the header and if the email, or smtp origination is from a server from a foreign tld have it just rejected. I can whitelist anything if need be in the future but as of now we don't do any business overseas and don't need to worry about blocking legit email.
I think this should be possible, however, I am unsure of the syntax for the file, where to put it and if wildcards are possible in domain blocking like
Thank you all,