From mboxrd@z Thu Jan  1 00:00:00 1970
Message-Id: <200305181938.h4IJcw526342@augusta.math.psu.edu>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] Re: Free Plan 9 "shell" accounts?
In-Reply-To: Your message of "Sun, 18 May 2003 12:25:42 PDT."
             <20030518192542.GA1174@thefrayedknot.armory.com>
From: Dan Cross <cross@math.psu.edu>
Date: Sun, 18 May 2003 15:38:58 -0400
Topicbox-Message-UUID: b0f4a464-eacb-11e9-9e20-41e7f4b1d025

> > oxymoron
>
> maybe Im going to look stupid for asking this, but whats wrong with
> qmail? Sure its a unix tool, and djb isnt always the nicest guy in the
> world, but it seems to work pretty darn well, compared with
> say...sendmail.

Qmail is okay.  The biggest single problem with it is that DJB is
firmly convinced that the thing to do is avoid latency, because SMTP is
slow.  So, he opens up many TCP connections to a single remote server
at once.  The result is that the remote server can get severely
overloaded, which makes it defer delivery.  You end up with this
happening in a slowly attenuating cycle, which can actually increase
latency.  Maybe this has been fixed with a qmail patch; I don't know.

Postfix solves this problem by using a slow-start style algorithm to
find the point at which it's transfering the most mail to a remote site
in parallel, without overloading it.  You trade a little bit of
increased latency at the beginning for greater efficiency overall.  But
Postfix is getting kind of big and bloated, itself.  :-(

	- Dan C.