Subject: Re: POP client???

From: Joe Brennan <[email-masked]>
Date: Thu, 16 Feb 95 10:06:41 EST

> 	I don't believe that IMAP puts much more, if any, strain on your
> system resources than POP.  I don't know where you got the impression
> that "server machine is more powerful" in the case of IMAP and not also
> in the case of POP.

In my previous message, my brain slipped and I typed CPU where I meant
memory.  Sorry about that.

IMAP holds INBOX in memory on the server throughout the time that the
client (pine) runs, while POP just sends the spool contents out to the
client.  This means the load on the server end is a lot higher when a
couple of hundred people run an IMAP client than a POP client.  Note
that we were using the mbox driver with IMAP, so what POP does is
similar in effect, that is, new mail gets appended to mbox as the user
runs pine.  Users of PC-based clients (PCPine, Mailstrom) connecting
IMAP to our mail server see their mbox as INBOX.

Joseph Brennan     Academic Information Systems
                   Columbia University in the City of New York
                   [email-masked]

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From: David L Miller <[email-masked]>
Date: Thu, 16 Feb 1995 15:48:32 -0800

On 16 Feb 1995, Joe Brennan wrote:

> Date: 16 Feb 1995 10:18:09 -0800
> From: Joe Brennan <[email-masked]>
> Newgroups: comp.mail.pine
> Subject: Re: POP client???
> 
> client.

That is true for berkeley format folders, but not if you use Tenex folders
as we recommend for dedicated mail servers.  The Tenex driver uses much
less memory and is more efficient than the berkeley driver... 

|\ |  |\/|  David L. Miller    [email-masked]  (206) 685-6240
|/ |_ |  |  Software Engineer, Pine Development Team   (206) 685-4045 (FAX)
University of Washington, Networks & Distributed Computing, JE-20
4545 15th Ave NE, Seattle WA 98105, USA

---

From: Mark Crispin <[email-masked]>
Date: Thu, 16 Feb 1995 18:43:08 -0800

> IMAP to our mail server see their mbox as INBOX.

This is only true if you use the standard unix "bezerk" format.  If you
use "tenex" (mail.txt) format, there is minimal memory usage.  Tenex
format is designed to permit random-access I/O, whereas bezerk needs to do
text rippling and so has to keep another copy the data around.

If you have a standalone server with no user file access from other 
programs, there is no reason not to use tenex format.

In any case, however, these are artifacts of a particular implementation,
and are otherwise unrelated to any differences between POP and IMAP.