POP3 (or just POP - Post Office Protocol) and IMAP (Internet Message Access Protocol) are protocols for email access. Both of them are supported on our servers, and you can use them to connect to your mail server.
IMAP is a protocol for accessing and handling email directly on the mail server.
POP, on the other hand, is an email protocol that mail clients use to download email messages from the remote email server.
The main difference between POP and IMAP is that IMAP manages email messages directly on the server, while POP downloads them locally, and you can manage them only on the computer where they were downloaded.
Both protocols have their advantages in certain situations. With IMAP, for example, all your email is stored in your mailbox on the server, and you can see your messages only when you are connected to the server. This allows you to connect from any computer with any email program and see all your mail and mail folders as they are on the server.
The Webmail application that we provide for email access uses IMAP. If you intend to use it for email, we would recommend that you set up your email program to use IMAP, too.
With POP, on the other hand, the messages are usually removed from the server when they are downloaded, and your email folders are set up only in the mail program on the computer you use to manage your email. POP can be used to manage your already downloaded email even when you are offline.
Another difference is that if you use IMAP, outgoing email may be stored on the server; if you use POP, though, outgoing messages will be available only locally.