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From: lindberg@cs.chalmers.se (Gunnar Lindberg)
Newsgroups: comp.mail.sendmail
Subject: Re: Heavily loaded hosts - (partial) retraction
Message-ID: <3154@fnatte.cs.chalmers.se>
Date: 25 Jul 89 12:45:37 GMT
References: <3140@fnatte.cs.chalmers.se> <218300005@uxc.cso.uiuc.edu>
Sender: news@cs.chalmers.se
Organization: Chalmers University of Technology, Sweden
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To summarize: There are a number of good reason *not* to implement my
"brilliant" idea of sendmail replying "421 I'm too busy":

    1)	Paul Pomes <paul@uxc.cso.uiuc.edu>:
	Thus the receiver will fork(), issue 421, and exit() for
	each message in the sender's queue.  This can bring a loaded
	uni-processor VAX to its knees.
    
    2)	Brian Kantor <brian@ucsd.edu>:
	If you have multiple mail servers (i.e., more than one MX host),
	refusing connections on one of them will cause incoming mail to
	be redirected to another of them. If instead you accept the
	connection and "421" it, the mail gets requeued on the sender
	and the other MX hosts are not tried.
    
    3)	Both:
	Current sendmails note that a host is refusing connections and
	on the current queue run will avoid trying to make additional
	connections to it.

Anyway, forget about my changes to "srvrsmtp.c" and "daemon.c" - the
original code does a much better job than I did!

However, I do think the changes to "conf.c", to make "getla()" work on
hosts with a frozen configuration and on Sequent are still valid.

	Gunnar Lindberg