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From: bzs@bu-cs.BU.EDU (Barry Shein)
Newsgroups: comp.mail.uucp
Subject: Re: cancelling mail messages
Message-ID: <2718@bu-cs.BU.EDU>
Date: Sun, 30-Nov-86 14:07:40 EST
Article-I.D.: bu-cs.2718
Posted: Sun Nov 30 14:07:40 1986
Date-Received: Sun, 30-Nov-86 20:46:11 EST
Organization: Boston U. Comp. Sci.
Lines: 26


I consider both reasons NOT to have such a feature compelling:

	1. It is very unclear under what circumstances you
	can technically cancel mail. For example, we are an
	ARPANET node and a mail message sent is usually gone
	in seconds.

	2. It is unclear whether this is an ethical practice,
	once you drop a letter in the mailbox you cannot retrieve
	it (legally.)

I think it all falls under the heading of "don't make promises you
can't keep" (a systems programming axiom I use often in such
circumstances.)

It is analagous to deleting a file, it is far better if the community
learns that once a file is deleted it is most likely gone. If you want
you can do with mail what some O/S's have done with files, mark them
for sending and ask later if they really want it to be sent. I would
find that annoying however (for letters, not files.)

I think you are asking for huge troubles once you give your community
any hint that a letter might be retracted, think about it.

	-Barry Shein, Boston University