IMAP (Internet Message Access Protocol) and POP (Post Office Protocol) are two different protocols (technologies) which are used to access email accounts. Review the differences and choose the protocol which is suitable for you. Each has its own advantages.
IMAP sync the messages and All mail boxes. Emails are stored on the server. It is the better option if you want to check your emails from multiple devices, like PC, laptop, tablet and other mobile devices.
POP does not sync emails. It downloads only "INBOX" emails from server to device leaving no record on server. POP3 is more useful only in case you want to keep all emails on single device.
Do not hesitate to contact our Support Team if you have further questions.