[Dovecot] Execute Script on LMTP Deliver?

[Edward Carraro]

Is it possible to have dovecot 2.0.8 using LMTP run a shell script each time
it delivers a message to a users mailbox?

I see there's an "execute = script /path/to/script" but when i added it to
lmtp service in 10-master.conf, it didnt do anything and stopped delivering
mail altogether

service lmtp {
  executable = script /usr/local/bin/test.sh u%

  unix_listener /var/spool/postfix/private/dovecot-lmtp {
   group = postfix
   user = postfix
  }

  inet_listener lmtp {
    port = 24
  }
}

$ ls -lh | grep test
-rwxrwxrwx 1 root  staff  270 2010-12-09 18:05 test.sh

$ cat test.sh
#!/bin/sh
USER=$1
echo $USER > /tmp/newfile


basically when a message arrives, it will execute a shellscript which will
notify another service that mail has arrived in their inbox