[Dovecot] problems with expire plugin

[Felix Rubio Dalmau]

Hi all,

	I'm experiencing problems to set-up the expire plugin in dovecot. This is the relevant part of my dovecot configuration

		dict {
		  expire = mysql:/etc/dovecot/dovecot-dict-expire.conf.ext
		}

		plugin {
		  expire = Trash 15 Junk 15
		  expire_dict = proxy::expire
		}

		protocol imap {
		  mail_plugins = quota zlib expire imap_quota
		}

	File dovecot-dict-expire.conf.ext looks like:

		connect = host=127.0.0.1 dbname=virtual_email user=<user> password=<passw>
		map {
		  pattern = shared/expire/$user/$mailbox
		  table = virtual_expires
		  value_field = expire_stamp

		  fields {
		    username = $user
		    mailbox = $mailbox
		  }
		}

	and the mysql schema for table virtual_expires is:
		+--------------+--------------+------+-----+---------+-------+
		| Field        | Type         | Null | Key | Default | Extra |
		+--------------+--------------+------+-----+---------+-------+
		| username     | varchar(75)  | NO   | PRI | NULL    |       |
		| mailbox      | varchar(255) | NO   | PRI | NULL    |       |
		| expire_stamp | int(11)      | NO   |     | NULL    |       |
		+--------------+--------------+------+-----+---------+-------+

	However, when I delete any mail from the Inbox, the table is not updated, and there are no messages in the log, although mail_debug is set to "yes"

	Does anybody has any idea on how to solve this issue?

	Regards!
Felix