How to Configure
Microsoft Outlook

IMAP (Internet message access protocol) offers a two-way communication between your cloud server and your email client(s) and devices. When you perform an action such as sending or receiving email it is immediately reflected on all your email configured devices. Also, if you are at work, and you begin a message, and save it, it will still be there when you log in from a different client or device.

IMAP is ideal for handling email between devices. IMAP's shortcoming is that your email is really only on your email server. You devices act as though the email is local but its not. They are reflecting images of email and folders sitting on the server. Because your email is not local, IIMAP poses a problem, in that, it can easily overload your mailbox quote. Once you exceed limits you must delete or archive email to continue. 

POP3, (Post Office Protocol 3) is (Our) the preferred method because of its simplicity. In POP, email is pulled off the server and sent to your local inbox. Control of how you organize email and folders is best handled by an APP such as MS Outlook. Because the email is local there is no concern for meeting a quota. With Outlook you can tell the server to store mail for a set period of days or weeks and then after that period is reached mail is removed. When you delete email from your Outlook it is deleted from the server after either the set period of time or when deleted from deleted items.

If you have multiple devices consider this scenario. Configure all portable devices that you take on the road with you and configure them for IMAP, on your portable devices and configure your office computer as POP3. This will be the device that will hold all of your email for eternity, if need be. Control server email by telling your desktop Outlook to leave email on the server for 21 days, at least, and then to delete all email deleted or deleted from deleted items. This will eliminate the need to worry about server based email quotas.