Sorry for the sidebar distraction, those uninterested in POP vs. IMAP
should hit D now...
On Fri, 30 May 2003, Tony Hain wrote:
Dave Crocker wrote:
The POP->IMAP example is excellent, since it really
demonstrates my point. IMAP is rather popular in some local
area network environments. However it's long history has
failed utterly to seriously displace POP on a global scale.
Could that be because from the end user perspective IMAP doesn't provide
any clear value over POP? Isn't IMAP all about shifting control of the
mail store from the end user into the hands of the mail administrator?
Tony,
I strongly disagree with your characterization (and I believe Dave's
assessment is only true for residential ISPs, not enterprises.)
My own interest in and support of IMAP is totally driven by my
end-user needs. IMAP lets me get at my INBOX from any of the multiple
machines I use every day. IMAP lets me selectively fetch headers and
body parts to save time over slow links. IMAP lets me access any of
my other incoming or archive folders from anywhere. IMAP lets me set
status flags on my messages. IMAP lets me know about new mail arrival
in real-time without hammering the server.
POP offers none of those benefits. (True, you can fudge #1 via "leave
mail on server", but without any status flags, that's a dismal
option.) IMAP is a functional superset of POP: it supports not only
"offline" (download-and-delete) access ala POP, but also "online" and
"disconnected" access modes (though I agree with the criticism that
"disconnected" capability, wherein local mail caches are automatically
synchronized with the server, is somewhat "under-represented" in most
IMAP clients.)
People who only use one computer (and who back it up regularly :), may
find relatively little benefit to IMAP --though I'd argue that
selective fetching is an increasingly big deal as low-quality wireless
Internet access becomes commonplace. Moreover, I believe the trend is
toward more people using multiple devices to access their mail.
Currently it may be true that most residential ISP customers fall into
the single-computer-user category (for their personal mail), but I
suspect an equally important factor is that few of those same
customers have ever heard of IMAP or why they might find it useful. It
is also true that many service providers are concerned about disk use,
and indeed need to expect that IMAP users might keep more mail on
their disks. Many small residential ISPs offer IMAP (for a sample,
see http://imap.org/products/providers.html) but I don't know of any
really large ones that do (although Milo assured me that @Home was
*going* to... :)
In contrast, I suspect that most enterprises use either Exchange/MAPI
or an IMAP-based solution (and of course Exchange also supports IMAP).
Hybrids are also possible, and those who need IMAP functionality but
wish to maintain control/responsibility for their mail store often run
their own IMAP server.
Therefore I claim that it is highly incorrect to suggest that IMAP
hasn't displaced POP "because from the end user perspective IMAP
doesn't provide any clear value over POP", or because it was "all
about shifting control of the mail store from the end user into the
hands of the mail administrator" --which I can assure you, it was not.
Cheers,
-teg