How can I lessen the update time in outlook 2013 with out deleting his folders/sub-folders?

I am working with an end user, who is using Outlook 2013 on Windows 7. Our company also uses Office 365.

The user currently has about 200+ folders/sub-folders. So every time the user opens up Outlook 2013 it takes hours to update, which prevents the user from seeing his most recent emails until it is finished updating.

The user does not use any rules. When he receives an email he deletes it or drag-and-drop it into the specific folder/sub-folder.

How can I lessen the update time without deleting the users folders/sub-folders?