inbox

[ssslow]

mail letter does not show opened or will not delete until mail has been
closed and opened again also cannot drag and drop emails to folders

 

[Gary VanderMolen]

If any messages can't be deleted, apply this Microsoft fix:

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

Although that article only mentions Outbox, it works for all mail folders.

If the problem continues, your antivirus may be interfering. Which
antivirus is it?