Re: Case sensitivity of user names

[Matti Aarnio <mea@nic.funet.fi>]

> On Tue, 2 Jan 1996, Matti Aarnio wrote:
...
> On another issue, I found mail bounced to one of our users whose
> entry in /etc/password reads:
> 
>   Ross: ....
> 
> zmailer finds no user 'ross'. :-(  I verified that zmailer
> rejected the address by telnetting to port 25 and doing a
> manual VRFY on the address Ross@blaze.net.au (ross@.. works
> fine).
> 
> How can I make local user names case INsensitive (shouldn't
> they be this anyway)?

	Ah yes, I remember having one user-account of "Esemi",
	and it did cause a bit of trouble too, when people
	sent email to there for ``esemi'', which didn't match..

220 castor.cc.utu.fi Server ESMTP+AUTH 2.99.21 #1 ready at Wed, 3 Jan 1996 09:03:29 +0200
HELO mea.cc.utu.fi
250  castor.cc.utu.fi Hello mea.cc.utu.fi
VERB
250-ZMailer SMTP server 2.99.21 #1: Mon Nov 20 11:43:04 EET 1995
250-Copyright 1990 Rayan S. Zachariassen
250 Copyright 1991-1995 Matti Aarnio
EXPN Ualfard@utu.fi
250 Alfard UUCP <Ualfard>
EXPN ualfard@utu.fi
550 no such user: <ualfard>

	The way it works is that if the target userid is ``all lowercase'',
	then any written form goes to the recipient, however mixed-case
	accounts are case sensitive!  Also the behaviour of EXPN does not
	necessarily match that of the actual delivery mechanism..
	All-uppercase or mixed-case input for lowercase account causes
	EXPN (and VRFY) to fail, however delivery succeeds:

$ Mail -v MEA@UTU.FI
Subject: test test
test...
.
$ router processed message 170054-1
s local mea mea@utu.fi 401
r       local MEA@UTU.FI MEA 65534
....
router done processing 170054-1
scheduler processing 170054-1
local mea@utu.fi MEA 65534: ok (sent)
scheduler done processing 170054-1

	Also <MeA@UTU.FI> goes ok, so there is no problem, because
	if the literal match (first choice) does not match, the
	``mailbox'' tries to lowercase the recipient name, match
	it to account, and deliver..

	There is no ``for final case, iterate all accounts and match
	case insensitive'', though adding it would not be that difficult.
	(But at large account sets it would cause the delivery failure
	 lookup to take considerable part of eternity..)

	Getting the  EXPN and VRFY to behave alike to the delivery
	should be rather straight-forward.  (I will look at it.)

	One way to handle such mixed-case addresses is to add  alias
	entry:
		# Canonic spellings of the mixed-case accounts
		# The key (left-side) MUST BE ALL-LOWERCASE
		mixed: MiXed

	and now all deliveries should go in just fine..  Some testruns:
		z# router mixed
		<mea.interactive@mea.utu.fi>: address: mixed
		(((local mixed MiXed g0)))
		z# router MIXED
		<mea.interactive@mea.utu.fi>: address: MIXED
		(((local MIXED MiXed g0)))

	After adding above-kind of mapping to  mailhost.utu.fi:
		EXPN ualfard@utu.fi
		250 Alfard UUCP <Ualfard>
	(when it previously gave an error..)

>  David

	/Matti Aarnio <mea@nic.funet.fi>