<!-- $Id: imap.html,v 4.0 2004/11/16 20:57:31 matt Exp $ -->

  <TITLE> All About IMAP</TITLE>
  <LINK REL="stylesheet" HREF="/includes/standard.css" TYPE="text/css">
  <META CONTENT="All about IMAP, the Internet Message Access Protocol" NAME="description">

<H1 CLASS="title">What is IMAP?</H1>

		<a href="http://www.imap.org/">The following was culled from the UW IMAP site</a><BR>
  <TR><TD COLSPAN="2"><BR>

<H1 CLASS="title">What is IMAP?</H1>

<P>IMAP stands for <STRONG>I</STRONG>nternet <STRONG>M</STRONG>essage <STRONG>A</STRONG>ccess
<STRONG>P</STRONG>rotocol.  It is a method of accessing electronic mail or bulletin board messages that
are kept on a (possibly shared) mail server.  In other words, it permits a "client" email program to
access remote message stores as if they were local.  For example, email stored on an IMAP server can be
manipulated from a desktop computer at home, a workstation at the office, and a notebook computer while
traveling, <STRONG>without</STRONG> the need to transfer messages or files back and forth between these
computers. <P> IMAP's ability to access messages (both new and saved) from more than one computer has
become extremely important as reliance on electronic messaging and use of multiple computers increase,
but this functionality cannot be taken for granted: the widely used <EM>Post Office Protocol</EM> (POP)
works best when one has only a single computer, since it was designed to support "offline" message
access, wherein messages are downloaded and then deleted from the mail server.  This mode of access is
not compatible with access from multiple computers since it tends to sprinkle messages across all of the
computers used for mail access.  Thus, unless all of those machines share a common file system, the
offline mode of access that POP was designed to support effectively ties the user to one computer for
message storage and manipulation.  </P>

<P>Key goals for IMAP include:</P>
<LI> Be fully compatible with Internet messaging standards, e.g. MIME.</LI>
<LI> Allow message access and management from more than one computer.</LI>
<LI> Allow access without reliance on less efficient file access protocols.</LI>
<LI> Provide support for "online", "offline", and "disconnected" access modes <SMALL>*</SMALL></LI>
<LI> Support for concurrent access to shared mailboxes</LI>
<LI> Client software needs no knowledge about the server's file store format.</LI>

<P>The protocol includes operations for creating, deleting, and renaming mailboxes;  checking for new
messages;  permanently removing messages; setting and clearing flags; server-based 
<A HREF="http://www.isi.edu/in-notes/rfc822.txt">RFC-822</A> and 
<A HREF="http://www.oac.uci.edu/indiv/ehood/MIME/MIME.html">MIME</A> 
parsing (so clients don't need to), and searching; and selective fetching of message attributes, texts,
and portions thereof for efficiency.</P>

<P> IMAP was originally developed in 1986 at Stanford University.  However, it did not command the
attention of mainstream email vendors until a decade later, and it is still not as well-known as earlier
and less-capable alternatives such as POP, though that is rapidly changing, as <A
HREF="http://www.imap.org/news/press.html">articles in the trade press</A> and the implementation of IMAP in more and more <A
HREF="http://www.imap.org/products/">software products</A> show.  (See <A HREF="http://www.imap.org/about/history+status.html">IMAP Status and
History</A> for a chronological overview of significant IMAP developments.) </P>

<P>There is a companion protocol to IMAP, developed at Carnegie Mellon University.  It is called the
"Application Configuration Access Protocol", or <A HREF="http://asg.web.cmu.edu/acap/">ACAP</A>, and
provides the same location independent access to configuration files, address books, bookmark lists, etc,
that IMAP offers for mailboxes.</P>

<P>*<SMALL> See <A HREF="http://www.imap.org/papers/imap.vs.pop.brief.html">Comparing Two Approaches to Remote Mailbox Access: IMAP
vs. POP</A> and <A HREF="http://papers/imap.vs.pop.html"> Message Access Paradigms and Protocols</A> for a detailed
discussion of the advantages of IMAP as a message access method.</SMALL></P>

		&copy; 1996-2003 <A HREF="http://www.washington.edu">University of Washington</A><BR>
  <TR><TD BGCOLOR="#660033" COLSPAN="2"><IMG SRC="images/red.gif" ALT=" " HEIGHT="3" WIDTH="1"></TD></TR>