Access to <user mailbox> not allowed by rule - Domain over storage limit!
Any mail sent to a certain eMail box on our Exchange 2003 SP2 server gets a bounce-back with the error as above. Here is the rest (names have been changes to protect the innocent):
Diagnostic-Code: smtp; 550 5.7.1 <senders mailbox> Access to <users mailbox> not allowed by rule - Domain over storage limit!
Last-attempt-Date: Thu, 01 Apr 2010 02:37:25 +0000
Also, limit settings, both global and local, are eliminated. The user mailbox is about 1.2GB. Mail sent to all other mailboxes goes through OK.