Since I setup procmail to bounce spam, the amount of spam I have received jumped from about 100 per week to 175 per week. I don't know if it's related, but I've decided to stop doing this. One thing that isn't quite perfect about that method of bouncing, is that the MTA (Postfix, in this case) doesn't reject the mail right away. It actually successfully delivers it (the sender knows this), and then only later does procmail bounce it. Maybe spammers are onto this method and treat this the same as replying to spam, i.e. confirming the address is indeed real. So, instead of bouncing spam, I'll just put it directly into my saved spam box (for bayesian learning). The only trick is how to make the message show up already as read. Otherwise, mail programs constantly say there are unread messages. For these obvious spam messages, I really don't care to read them anymore. Since I use the maildir format, I had to use some procmail magic to set the "Seen" flag. Read on for my procmail recipes, now.

    # Delivers the message to the "new" subdir, setting LASTFOLDER
    :0 c

    # Extract the filename, move to "cur", and add the "Seen" flag
    :0 ai
    * LASTFOLDER ?? ()\/[^/]+^^
    | mv "$LASTFOLDER" "${SAVED_SPAM}/cur/$MATCH:2,S"