Originally Posted by orgullodemexico
On a couple of occasions I have tried to forward and old email, but it failed.
If you're on BIS 2.0 and getting an 'unlisted message error' it's because BIS is trying to reference the original message on the originating mail server and failing. I'm not sure if this would be affected in older BIS.
Try to forward using another address. Scroll up to the top of the message where is says 'Send Using' and select a different account. This may force it to look on the handheld to forward it.