Messages Downloaded Then Disappeared

I recently started using Em Client and it has been working fine until this morning.  I downloaded about a dozen new messages and only got a quick glance at them before they totally vanished.  They are not in my trash or junk mail folders so I have not deleted them or junked them by mistake.

I logged on to my web mail and the messages are all still there.  Can anyone tell me what caused this and is it likely to happen again?   

How is your account setup - IMAP or POP3?

Did you look in local folders to see if they are there?

The account is IMAP and they are not in the local folders.

If they are still visible in the web interface, then they must still be there somewhere. Maybe in a sub folder somewhere?

Right-click on your Inbox and choose Properties > Repair. After the re-sync is finished, see if they are there.