This is a known issue with Outlook 2013 connecting via IMAP.

Symptoms:

• Mail isn't populating
• Sent Items, Outbox, Junk Email folder etc. show up as the subfolders of the Inbox folder.

Until Microsoft releases an update to fix the issue, use the following workaround:

Note: Please create a backup of Sent Items folder before making any changes.

1. In Outlook 2013, navigate to Home > Info > Account Settings > Account Settings:
   
   
2. Select the IMAP account and click Change (or double-click the IMAP account name)
3. Navigate to More Settings > Advanced and enter INBOX in the Root folder path field
4. Click OK > Next > Finish
   
   

Tags: Email, Outlook