Internet mail is handled by various protocols. While all of these are designed to deliver your mail to you, there are some fundamental differences. On servers where you have a choice between different delivery protocols, you will need to select the protocol most suited to your situation.

• POP

POP or POP3 stands for Post Office Protocol. This mail delivery protocol was the standard for a number of years, particularly when server-side storage space came at a premium. Most distinctively, a client using POP to check your e-mail will retrieve all of the messages from the server and store them on your computer before opening or reading any of them. (You may select an option not to delete these messages from the server with most clients; doing so will cause you to download these messages again each time your check your mail.) This choice is handy when you have an inconveniently small storage quota on your mail server, or you prefer to retain all of your messages locally so that they can be accessed offline. Once downloaded, you can read messages retrieved with POP anytime without reconnecting to the internet. The biggest drawback to this, for many, is that you can only access previously-read messages from the computer onto which you downloaded them. In a multiple-computer environment, this can be a severe disadvantage.

For more information on the POP protocol, Click Here.

• IMAP

IMAP stands for Internet Mail Access Protocol. The most distinctive feature of IMAP is the fact that your mail messages remain on the server, instead of being downloaded to your computer. This is advantageous if you access your mail from multiple computers, or if you expect to need access to your mail from any computer on the World Wide Web. Checking your mail with a client or web-based environment using this protocol will allow you retain your messages in a universally-accessible place for access whenever and wherever your need them. IMAP supports the use of folders for mail organization, but instead of organizing the messages on your local computer, these folders are kept on the server as well. Another advantage to IMAP is quicker access to mail. If you access your e-mail from a slower connection, such as modem dial-up, you will notice a substantial increase in speed; only the message headers are initially downloaded, so you can choose to download, open, and read only those messages of interest to you at that time. One drawback to using IMAP and saving messages on the server is that you will be restricted by any quota limitation the administrator may set. Once you have stored enough messages to fill your quota, e-mail may be returned to the sender.

For more information on the IMAP protocol, Click Here.