Courier Maildrop
================

Shanker Balan
http://shankerbalan.com/

Changelog:

* Wed May 28 12:39:55 IST 2003
- Updated maildroprc to test for .Spam only if the SPAM tag is set. Should make
  the deliver more efficient now
* Thu May 22 15:44:40 IST 2003
- First cut

Auto filtering using Maildrop
=============================

Overview:

1. Spam comes in to the MTA
2. MTA hands it to the mail sanitizer (SpamAssassin)
3. SpamAssassin tags the mail with "X-Spam-Flag: YES" and hands it back the MTA
4. MTA invokes Maildrop as LMTP
5. Maildrop reads etc/maildroprc
6. Create ~/Maildir/.Spam (if it does not exist) and deliver to ~/Maildir/.Spam

Assuming that you have configured your MTA to use SpamAssassin and use maildrop
for delivery, add the following recipe to your global "maildroprc"

###
### /usr/local/etc/maildroprc
###

if ( /X-Spam-Flag: YES/ )
{
	
	`/bin/test -d $HOME/Maildir/.Spam/`
	
	if ($RETURNCODE != 0)
		{ 
			`/usr/local/bin/maildirmake $HOME/Maildir/.Spam/`
				if ($RETURNCODE==0)
				{
					logfile maildrop.log
					log "Creating $HOME/Maildir/.Spam/"
				}
				else
				{
					logfile maildrop.log
					log "Failed creating $HOME/Maildir/.Spam/"
				}
		}
	
	logfile maildrop.log
	to Maildir/.Spam/
}

###
### Maildrop Log
###

root# tail -f /home/sonz/maildrop.log

Creating /home/sonz/Maildir/.Spam
Date: Thu May 22 15:02:37 2003
From: Shanker Balan <shanu@mydomain.com>
Subj: $15,500 to over $650,000 in FREE Grant Money
File: Maildir/.Spam                                                     (2179)


###
### Notes
###

- if Maildir ~/Maildir/.Spam/ does not exist, then maildrop will create a mbox
  style mailbox called .Spam and deliver to that instead which breaks
  Courier-IMAP. The mailbox must pre-exist as a Maildir. AFAIK, Maildrop does
  not have the capability to create Maildirs like procmail does.

- Amavisd/SpamAssassin's "tag_level" has been set to "3" and "tag2_level" is
  set to "4". Also, "final_spam_destiny" is set to "D_PASS", spams are not
  bounced (the default is to REJECT)

- The "." in ".Spam" is to make the Maildir compatible with Courier-IMAP

- This recipe is probably very inefficient on a busy mail server and has not
  been tested on one (yet). I cooked this up for use on my local box.

###
### URL
###
HOWTO Install Spamassassin to work with Maildrop and the Courier Mail Server:
http://www.buberel.org/linux/courier-maildrop-spamassassin.php