Subject: Re: Internet Draft for flexible proxying of the mail protocols

From: [email-masked] (Kai Henningsen)
Date: 02 Oct 2000 20:40:00 +0200

[email-masked] (Philip Hazel)  wrote on 29.09.00 in <[email-masked]>:

> On 28 Sep 2000, Russ Allbery wrote:
>
> > We much prefer POP from the server side.
>
> We don't, but then we have permanently connected clients that keep
> probing for new mail at regular intervals. POP requires a password
> authentication for each probe, and a download of the entire mailbox to
> check for new messages. When the users set their probe interval

Um, there's *nothing* in POP that requires "a download of the entire  
mailbox to check for new messages".

The copying of mbox files you probably mean is a feature of POP servers  
which use mbox mail files, which certainly isn't the best design in the  
world. Try the same with, say, Maildir, or any other mailbox format that  
doesn't require you to rewrite the whole mailbox if you just want to, say,  
delete a message, or change a status flag on a message, and the problem  
should go away.

Don't blame the protocol for a suboptimal implementation.

MfG Kai

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From: Terje Bless <[email-masked]>
Date: Tue, 3 Oct 2000 18:45:54 +0200

>mailbox to check for new messages".

Doesn't UIDL return a complete message list (message # plus MD5)? IIRC, the
only way to avoid this is to use a "last message" pointer (which doesn't
work well) because POP has no equivalent to NNTP NEWNEWS.

It's a bit hard to tell given the implementation specific problem you
mentioned, but it seems to me that there is significant overhead involved a
trivial mail check using POP. Then again, I've never written a POP MUA of
that magnitude so I may be wrong.

-- 
As a cat owner, I know this for a fact...
Nothing says "I love you" like a decapitated gopher on your front porch.

---

From: Philip Hazel <[email-masked]>
Date: Tue, 3 Oct 2000 20:36:31 +0100 (BST)

> mailbox to check for new messages".

I have to confess I don't know much about POP. I'm trying to interpret 
comments I hear from people who do run it. I guess this must apply to 
the way it gets used in some configurations/implementations.

> world. 

Oh, absolutely. We use them because we are stuck with them for various 
reasons (not a sealed server, for a start). A large, single mbox file
full of messages is a disaster at start-up for pretty well any MUA.

> Don't blame the protocol for a suboptimal implementation.

I should have been clear that I was talking about particular 
implementation/configuration circumstances, not "every possible way you 
could use POP". Sorry.

-- 
Philip Hazel            University of Cambridge Computing Service,
[email-masked]      Cambridge, England. Phone: +44 1223 334714.