Comment 1 for bug 990689

Thanks for reporing this!

Does it happen immediately after startup/login, or it dissapears some time after it?
Did you modify any configuration options?
Can you please paste here output of these commands (wait for a minute after running these, and press Ctrl+C to stop the process):
  pkill -f unity-mail
  unity-mail

In future, please report bugs using "ubuntu-bug unity-mail" command.