IMAP vs. POP

• Which Protocol We Recommend
• IMAP
• POP

We recommend that most people at the University of Virginia use IMAP configuration. IMAP allows you to move from computer to computer and yet access your messages stored in the server mailbox or in folders on the server as if they were resident on the computer you are using to access your email messages. It also provides for faster access to your messages for those who receive many messages or who keep a large number of messages in their mailbox.

IMAP ((Internet Message Access Protocol) uses an approach to managing your access to your messages that gives you what you need when you need it. When you first access your mailbox, it gives you the information about the messages in your mailbox - if you have read them or not, their sender, their subject, when they were sent, etc. It also tells you what folders you have available. Then, as you work with your messages, it does what you ask when you ask it. If you want to read a specific message, IMAP provides the message to you. If you want to move the message to a folder, IMAP makes the move as you specify. If you want to delete a message, IMAP deletes the message you indicate. This type of interaction is called a client-server interaction because you, the client, make a request and, through IMAP and your Email program, the server where your messages reside responds.

The POP (or Post Office Protocol) uses an approach to managing your mail that is similar to that of having a mailbox with the U.S. Postal Service.

If you have a mailbox at a Post Office, to process your mail you:

• go to Post Office where your letters are delivered
• open the box
• remove your letters from the box
• take your letters back to your home to read, respond, store or throw away.

With POP email programs, to process your messages::

• you make a connection to the server on which your incoming messages are stored (here at U.Va., this server has the name Central Mail Service or CMS)
• you login to the server
• the POP email program copies to the computer you are using all the messages you have on the server and, in the normal, default mode, usually deletes the messages from the server
• you then process the messages on your computer.
• you work with your messages on your computer, reading new messages, moving messages to storage in folders on your local computer, etc.
• at some point, you may send commands to the server where your messages are stored to delete messages from that mailbox, send responses to messages you have received, etc.

Like other POP email programs, Eudora can be configured so that it leaves your messages on the server, so that your messages remain on the server. While this configuration may seem optimal as it provides for access to all messages from multiple locations, please be aware of the following:

• If you work from multiple locations, all messages that are new to a location (for example, your home computer) must be downloaded to that location, even if they have been read at another location (for example, in an office.)
• If messages are never deleted from the server mailbox, the mailbox can become so large that it is impossible to download messages from it.
• A message that is stored in a local folder is accessible only on that computer - it is difficult (and sometimes impossible) to read that message from another computer.