Re: POP3 woes

[Peter Bloomfield <PeterBloomfield bellsouth net>]

Hi Albrecht:

On 02/10/2017 03:13:22 PM Fri, Albrecht Dreß wrote:
> Hi Peter:
>
> Am 10.02.17 18:43 schrieb(en) Peter Bloomfield:
> > So I'm guessing it's an incorrect implementation of pipelining in that "IMPLEMENTATION jpop-0.1" server.
>
> The version number does not inspire confidence...

Yeah, right?

> Anyway, I wonder if pipelining is a really required feature?  My assumption is that the communication speed 
> is basically limited by the network bandwidth, and thus the gain introduced by it is somewhat limited.  As 
> Balsa is running multithreaded, I guess the user won't even notice if we disable it completely.
>
> Or am I completely wrong here?

A high-latency connection would suffer--think satellite. On near-broadband, I can see a momentary pause between 
messages while the "RETR nn" command is sent, but I'd guess it's at the millisecond level. So, I feel that 
it's worth keeping pipeline capability, but we definitely need a fix for this broken server.

It's actually quite easy to fix for this particular server: the IMPLEMENTATION is part of the CAPA response, 
so we can easily detect that we're talking to jpop-0.1 and ignore its PIPELINING capability. If other servers 
had the same problem, we could install a blacklist, but at this point it would have only a single entry, so 
hard-coding seems adequate. I'm thinking of adding PopHandle::does_not_pipe.

One alternative would be to add an "Enable pipelining" checkbox to the SMTP server dialog, but its purpose 
would be obscure, and it's not clear how a user would know to disable it, so I'm inclined against that solution.

Thoughts?

Peter