Microsoft Outlook Question:

The POP (Post Office Protocol 3) protocol provides a simple, standardized way for users to access mailboxes and download messages to their computers. When using the POP protocol all your email messages will be downloaded from the mail server to your local computer. You can choose to leave copies of your emails on the server as well. The advantage is that once your messages are downloaded you can cut the internet connection and read your email at your leisure without incurring further communication costs. On the other hand you might have transferred a lot of message (including spam or viruses) in which you are not at all interested at this point. See also POP3 Description (RFC)