The user hasn't checked their mail in a while, so their mailbox is disabled

Sent from my Verizon Wireless BlackBerry

-----Original Message-----
From: John Cunniff <[log in to unmask]>

Date: Tue, 26 Jun 2007 16:25:53
To:Christopher Wilson <[log in to unmask]>
Subject: Error message help


Hello to anyo9ne:

5.1.1 550: user@domain.com...Due

 to
                            extended inactivity new mail is not currently being
                            accepted for this mailbox.

I wonder what does that means? I really don't understand this.

Thanks!
Johnny :)