🚀 go-pugleaf

karl.kleinpaste@osc.edu writes:

>Rayan's mailer is unquestionably to be awarded Most Picky Mailer Ever
>Devised, but it has the good taste to deliver anyhow, in view of the
>wide disregard for this particular bit of syntactic pedanticism.

The above situation is a recipe for disaster.

Imagine, if you will, a message sent to a very large international
mailing list with a completely trashed To: header, but with the
envelope intact.  What is a mailer to do?

	[a]	Bounce the message as undeliverable.
	[b]	Continue to process the message, possibly logging an
		error.
	[c]	Continue to process the message AND send an error to
		the sender.

If you said [c], that's what sendmail does; and it's wrong.  There was
an excellent example of this exact problem last week (see Erik Fair's
note to a bunch 'o lists including tcpip and risks).  The message
caused every sendmail that touched it to send an error message back to
the sender, in some cases multiple times.  Distributed systems are
funny that way.

If you said [a], I'd argue that you're still wrong, so long as the
message will remain in an environment where an envelope exists, as you
would be violating the robustness principle.

That leaves [b] (preferably logging an error message).
-- 
Eliot Lear
[lear@turbo.bio.net]