IMAP POP3
What does it stand for? Internet Message Access Protocol Post Office Protocol
Are messages kept on the server? YES Maybe (you may specify this in your client)
Is my account storage quota affected? YES - Any mail folders you create (as sub-folders of your INBOX) reside in your account, and therefore affect the amount of space you use (and the amount of mail you can store). NO - By default, all messages are downloaded to your computer and deleted from the server. Therefore, the amount of mail you can store is limited only by the size of your hard drive.
Can I access my mail from anywhere? YES - Since IMAP keeps all mail in a central location (the server), you can set up IMAP on multiple computers or access through webmail and always be able to see all your messages. NO - POP automatically downloads mail to the local computer, so if you try to set up POP on another computer, you won't be able to see old messages, and newer mail will be out of synch.
How fast is it? Faster: IMAP retrieves only the message headers when you check your mail; it doesn't retrieve the entire message until you actually read it. Slower: POP downloads every message in its entirety to your computer, which can take longer with large messages.
This protocol is suitable for... ...users who want access to all their mail from multiple computers or locations. ... users who access their mail from only one location.