An unknown error has occurred in outbox.

[gene-o]

When I try to delete or move a certain message "An unknown error message has
occurred " appears. How do I delete or move this message ?

 

[Guest]

When I try to delete or move a certain message "An unknown error message
has
occurred " appears. How do I delete or move this message ?

Download and install this fix, with Windows Mail not running:

http://support.microsoft.com/default.aspx/kb/941090

Although it's labelled as for mail stuck in the Outbox, it also
works in other folders. If you don't know whether to use
the 32-bit version or the 64-bit version, try the 32-bit
version first. Certain common antivirus programs, such as
most of those from Norton or McAfee, or a recent one
from Trend, tend to cause such problems, although not
immediately. If you have such a program, remember
where to find the fix - you are likely to need it again.