time machine restore - email problems

Hi there

I'm trying to restore email - either individual messages or folders from a local Time Machine back-up - yesterday's. I can see the mail I need to back up in the local (white coloured) snapshot listings. I click restore, the machine processes the request and then a blank screen appears in Mac Mail with 'No mailbox selected'. I've dug around in Mail and can't find the restored mail anywhere. All operating systems and versions of Mail are the same.

Any ideas? Thanks very much.