Run a script after receipt of email

==== Required information ====
- iRedMail version: 0.8.3
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MYSQL
- Linux/BSD distribution name and version: Ubuntu 12.04 LTS
- Related log if you're reporting an issue:
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Hello,
I wish I run a script after the receipt of mail in the mailbox.

I tried in "master.cf" but I lost the mail, it never arrives in the mailbox

An idea? thanks