Messaging Interface has returned an unknown error

[ZipperHeadMan]

Yes, this error is fairly common. Perhaps someone can point me in the right direction.
Here's my platform:

XP Pro SP1
Office XP stnd SP3
Outlook 2002
Exchange 2003 on Windows 2003

I can connect to the mailbox when I launch outlook. However, when I press the "Reply to All" button I get the old' Messaging Interface has returned an unknown error" error.

There is no PST file in use.
Deleted folder is empty.
Inbox/Sent all with minimum messages within.

ANY IDEAS OR IS MICROSOFT SCREWING WITH MY MIND?

 

[tylerdurdan66]

I have this same problem this moring and found out the user had over 14 thousand messages in the deleted items folder. She cleaned it out and this fixed the error