townx

"most of it gets stopped by the Postfix server using Spamassassin"

I don't think this part is right. From wiki.apache.org/spamassassin:

"SpamAssassin itself will not delete any emails. It's only a filter which reads email in, and passes that same email out, modified in some way. If you want to delete emails, or redirect emails, you need to do it in whatever program calls SpamAssassin. "

The site then goes on to explain how to set up a procmail filter to drop spam at the server, it that is what you want to do.

In your case, do you think what is happening is that Thunderbird's Bayesian filter can learn what is junk instantly because of SpamAssassin headers? Thus you can achieve your end result, very little spam in the Inbox, but all the filtering is done by Thunderbird. I don't see Postfix dropping mail on the floor. Please correct me if I am wrong.

Thank you for this mini-howto. I used it to set up Spamassassin on an Ubuntu server running Courrier IMAP in literally minutes, and it is working great. I also use Thunderbird. It is also easy to set a filter in Squirrelmail (web mail) to filter spamassassinated messages to the Inbox.Junk folder:

options/message filtering:

If Header contains X-Spam-Flag: YES then move to Junk