We strongly recommend all our customers to use IMAP over POP.
IMAP is newer and faster! The other advantage is that message status (which ones are read, unread, replied to, etc) is stored on the server so will be the same on all your clients (mail on your desktop, mobile, etc).
You can also use folders on IMAP to sort and manage your mail (folders which if anything happens to your computer are stored safely on the server). You can also save your sent mail in IMAP as well.
IMAP offers many advantages over POP, though we have no plans to phase out our POP service.