Crazy exchange issue

[Voltage]

Hi,

A particular client emails me they get this bounceback:

[email protected]
This recipient's mailbox is undergoing maintenance and can't accept this message at this time. Microsoft Exchange will not try to redeliver this message for you. Please try resending the message later, or provide the following diagnostic text to your system administrator.

Everyone else but this specific client is absolutely fine. They are also not being spam blocked by messagelabs.


Exchange 2007 Enterprise by the way.

 

[Voltage]

oh, and its not under maintenance

 

[PR.]

Not any odd characters in the recipients email address?

I've had a few recently where certain clients have been unable to send emails to certain users as the senders email system can't handle unusual characters, usually '.

Could try adding a new email address to the account and see if mail is delivered to that one.

 

[NightShadow]

Is the problem the same for both new emails and replying? Also if they are running exchange is there and internal email address setup on their Exchange which is the same?