IMAP vs. POP
There are many different methods for delivering electronic
mail. One method, called Post Office Protocol (POP), moves
your email (on demand) from the central inbox to a single
desktop computer. When you start a POP email program (for
example, Eudora on a Macintosh), all the mail in your inbox
is transferred to your desktop computer. Once that mail is
forwarded, it is usually deleted from the server, and the
connection between the mail server and your desktop
computer is closed.
In contrast, IMAP, the protocol offered by C&C, uses a
client-server model, in which your mail program (for
example, Mailstrom on a Macintosh) is a client that
interacts throughout a mail session with your inbox on a
computer known as the mail server.
The advantages of POP include:
-
Minimum use of connect time; an issue if you pay by the minute
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Minimum use of server resources
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More software is currently available for POP than for IMAP
On the other hand, IMAP has even more compelling advantages
over POP as the foundation of a campus email system. These
include:
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Access to your inbox from any location on the network
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Access to your inbox from different computers
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Faster start-up time, as only message headings are transferred
initially
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Optimization for low-speed links
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Ability to handle very large messages (e.g., MIME messages)
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Ability to fetch individual MIME attachments
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Ability to access non-email information (e.g., Netnews)
In addition, since IMAP is a functional superset of POP, IMAP
clients may be designed to offer POP-style bulk transfer in
order to minimize connect time and server resources.
University of Washington Computing & Communications
Windows on Computing, No. 13, May 1993
newsltr@cac.washington.edu