case sensitive user name (FOO@BAR.COM v. foo@BAR.COM)

'For some hosts the user name is case sensitive, and SMTP
implementations must take case to preserve the case of user names as
they appear in mailbox arguments. Host names are not case sensitive.'


Is this still the case? There can two different users, FOO and foo,
but that'd be a bad idea, anyway. It would've been chaos were host
names case sensitive, of course.

Is there a real-life example of case sensitive user name e-mail
addresses? I'm just curious if there's a host out there which uses
this.

thanks,

Thufir

Re: case sensitive user name (FOO@BAR.COM v. foo@BAR.COM)

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hawat.thufir@gmail.com writes:

> Is there a real-life example of case sensitive user name e-mail
> addresses? I'm just curious if there's a host out there which uses
> this.

Linux and Unix account names are case sensitive, and have been this way for
a long time.

Some mail servers may silently translate all local mail addresses to
lowercase, but some may not.


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Re: case sensitive user name (FOO@BAR.COM v. foo@BAR.COM)

Sam wrote:
[...]
> Linux and Unix account names are case sensitive, and have been this way for
> a long time.
>
> Some mail servers may silently translate all local mail addresses to
> lowercase, but some may not.
[...]

Right, but this (slightly) predates e-mail. I'm just curious if
there's actually a *nix admin who has user foo and FOO, and perhaps
Foo, and, how that's dealt with. Oh well :)


-Thufir

Re: case sensitive user name (FOO@BAR.COM v. foo@BAR.COM)

On Fri, 14 Jul 2006, hawat.thufir@gmail.com wrote:
> Is there a real-life example of case sensitive user name e-mail
> addresses? I'm just curious if there's a host out there which uses
> this.

Multics userids were mandatory case-sensitive.

-- Mark --

http://staff.washington.edu/mrc
Science does not emerge from voting, party politics, or public debate.
Si vis pacem, para bellum.

Re: case sensitive user name (FOO@BAR.COM v. foo@BAR.COM)

On Fri, 14 Jul 2006, hawat.thufir@gmail.com wrote:
> Right, but this (slightly) predates e-mail. I'm just curious if
> there's actually a *nix admin who has user foo and FOO, and perhaps
> Foo, and, how that's dealt with. Oh well :)

I've seen it done on UNIX systems. It is quite annoying.

Most UNIX mail software coerces input userids to all-lowercase, or first
tries the input form and then tries an all-lowercase form if the input
form isn't in the password database. The UNIX password file itself is
case-sensitive, as is most non-mail software that references userids.

As I noted earlier, Multics was case-sensitive on userids.

The Tenex and TOPS-20 systems of the past coerced to uppercase. They
could have lowercase user names but the system made it sufficiently
painful (by design - you had to prefix each lowercase character with
CTRL/V to prevent it from being coerced to uppercase) that nobody ever had
such user names.

Windows NT preserves case, but is case-insensitive as to matching. This
is probably the best design of the lot.

There was quite a catfight years ago as to whether all-uppercase or
all-lowercase userids were "easier to read" with both sides offering
completely unconvincing arguments to bolster their positions. The one
thing that just about everybody agreed on was that case-sensitivity in
userids was a really, really(!!), bad idea.

-- Mark --

http://staff.washington.edu/mrc
Science does not emerge from voting, party politics, or public debate.
Si vis pacem, para bellum.

Re: case sensitive user name (FOO@BAR.COM v. foo@BAR.COM)

hawat.thufir@gmail.com writes:

> 'For some hosts the user name is case sensitive, and SMTP
> implementations must take case to preserve the case of user names as
> they appear in mailbox arguments. Host names are not case sensitive.'
>
>
> Is this still the case? There can two different users, FOO and foo,
> but that'd be a bad idea, anyway. It would've been chaos were host
> names case sensitive, of course.
>
> Is there a real-life example of case sensitive user name e-mail
> addresses? I'm just curious if there's a host out there which uses
> this.

Well, if 'user' is on context of mailbox addresss user@domain
then it actually can be

user+detail@domain

For that 'detail' case is often significant. For example when
that 'detail' is done with common sendmail configuration trick,
where sendmail searches .forward+detail from user's home directory.


> thanks,
>
> Thufir

/ Kari Hurtta

Re: case sensitive user name (FOO@BAR.COM v. foo@BAR.COM)

hawat.thufir@gmail.com wrote:
> Sam wrote:
> [...]
> > Linux and Unix account names are case sensitive, and have been this way for
> > a long time.
> >
> > Some mail servers may silently translate all local mail addresses to
> > lowercase, but some may not.
> [...]
>
> Right, but this (slightly) predates e-mail. I'm just curious if
> there's actually a *nix admin who has user foo and FOO, and perhaps
> Foo, and, how that's dealt with. Oh well :)

But we aren't talking about (Unix or other) "user"s (Mark's term
userid) in the sense you are referring to ("*nix admin"), are we? I.e.
we are not talking about *login* (i.e. passwd(4)) names, but about the
username part of an *email address*, quite a different animal. I.e. we
are talking about hawat.thufir, not about hawatt (or whatever).

So the question is whether a *mail* admin would have a mailbox/
account/user/ HAWAT.THUFIR, hawat.thufir, Hawat.Thufir, etc..

FWIW, I have both some lower case as some mixed case email addresses,
albeit not on the same system/MSP.

Re: case sensitive user name (FOO@BAR.COM v. foo@BAR.COM)

Frank Slootweg writes:

> hawat.thufir@gmail.com wrote:
> > Sam wrote:
> > [...]
> > > Linux and Unix account names are case sensitive, and have been this way for
> > > a long time.
> > >
> > > Some mail servers may silently translate all local mail addresses to
> > > lowercase, but some may not.
> > [...]
> >
> > Right, but this (slightly) predates e-mail. I'm just curious if
> > there's actually a *nix admin who has user foo and FOO, and perhaps
> > Foo, and, how that's dealt with. Oh well :)
>
> But we aren't talking about (Unix or other) "user"s (Mark's term
> userid) in the sense you are referring to ("*nix admin"), are we? I.e.
> we are not talking about *login* (i.e. passwd(4)) names, but about the
> username part of an *email address*, quite a different animal. I.e. we
> are talking about hawat.thufir, not about hawatt (or whatever).
>
> So the question is whether a *mail* admin would have a mailbox/
> account/user/ HAWAT.THUFIR, hawat.thufir, Hawat.Thufir, etc..
>
> FWIW, I have both some lower case as some mixed case email addresses,
> albeit not on the same system/MSP.


And username part (left side of @ on e-mail address) may include also
other data than just username as I previously mentioned. Thse data may
(and often/sometimes is) case sensitive.

/ Kari Hurtta

Re: case sensitive user name (FOO@BAR.COM v. foo@BAR.COM)

On Sun, 23 Jul 2006, Frank Slootweg wrote:
> So the question is whether a *mail* admin would have a mailbox/
> account/user/ HAWAT.THUFIR, hawat.thufir, Hawat.Thufir, etc..

It has happened that there have been distinct mail addresses that differed
only by case to the left of the @: e.g., Linda duPont could be
LduPont@host while Larry Dupont would be LDupont@host (same host).

More commonly, it has happened that a mail address has been rejected for
delivery due to incorrect case to the left of the @.

The foolishness of doing either is generally recognized, and has been for
decades. Nonetheless, there were some vocal partisans of this behavior
some 30 or so years ago. Consequently, the email standards to this day
allow it.

-- Mark --

http://staff.washington.edu/mrc
Science does not emerge from voting, party politics, or public debate.
Si vis pacem, para bellum.