If you are using Outlook 2013 and use IMAP email you may find your sent items and other folders do not show up correctly and/or emails you send out stay in your outbox even though they actually do go to their recipients properly.

do this

Some IMAP accounts need a root set - so goto file, account settings, double click on the account then More Settings, Advanced. Type inbox in the Root field. (if you have /inbox already there, REMOVE the / and then save)