There is no official fix.
Best solution is to upgrade to Windows Live Mail:
http://get.live.com/betas/maildesktop_betas
Gary VanderMolen
"robertls" <robertls@discussions.microsoft.com> wrote in message news:88BD3F40-2CAB-4B56-8DC5-190B12D2B772@microsoft.com...
> One message keeps coming up with "unknown error" and that you can't delete
> the message. I see dozens of people have the problem. What can you do to
> get rid of the stupid problem?
> --
> robertls