Redmine

i use the EmailReceive : http://www.redmine.org/projects/redmine/wiki/RedmineReceivingEmails

Very nice and good...but our mail server use "vacation" message.
redmine download mails from mailbox and import those mails with cron (five minutes)
and send mail for users. Mail server is "vacation" this user and reply.
redmine download and import and send, mail server send a reply....
infinite loop

Have a filter for this case? From/Sender not ok, it's redmine user.
Subject: "Autoreply" , not the "Re: [xxxxxxx #123]" .

it's an autoreply mail, from mail.foo.hu

-------- Eredeti üzenet --------
Received: from Debian-exim by mail.foo.hu with local id 1T8Wps-0006lI-Px for <redmine@foo.hu>; Mon, 03 Sep 2012 15:37:04 +0200
From: celtic@foo.hu
To: redmine@foo.hu
Subject: Autoreply
In-Reply-To: <redmine.journal-41497.20120903153704@foo.hu>
References: <redmine.issue-4895.20120814111731@foo.hu> <redmine.journal-41497.20120903153704@foo.hu>
Auto-Submitted: auto-replied
Message-Id: <E1T8Wps-0006lI-Px@mail.foo.hu>
Date: Mon, 03 Sep 2012 15:37:04 +0200

test vacation volt

If this email downloaded and imported to redmine, sent mail to celtic@foo.hu, mail server send and autoreply and infinite loop :(

How know redmine which project and issue import in?