[Info-vax] bizarre SMTP problem

[David J Dachtera]

Arne Vajhøj wrote:
> 
> David J Dachtera wrote:
> > Steven Underwood wrote:
> >> "Bob Eager" <rde42 at spamcop.net> wrote in message
> >> news:176uZD2KcidF-pn2-PXhqF33pn2BN at rikki.tavi.co.uk...
> >>> On Thu, 9 Apr 2009 19:57:15 UTC, JF Mezei
> >>> <jfmezei.spamnot at vaxination.ca> wrote:
> >>> Then it appears to be a bug, since '+' is perfectly valid as a character
> >>> in an email address, as per RFC 2822 section 3.4.1.
> >> That may be, but there are lots of systems that do not honor plussed
> >> addressing.  My mail provider (SpamCop.net) allows for plussed addressing
> >> but many web based systems find those addresses to be illegally formatted.
> >
> > Such characters are not valid in UN*X usernames for many flavors of
> > UN*X, nor would it be allowed on VMS. So, it seems likely that an
> > attempt to verify the existence of such a user on a VMS or UN*X
> > receiving end would be likely to fail.
> >
> > The protocol itself my not disallow it, but is that a valid username on
> > the receiving system, and if so, how is that validated?
> 
> The part before the @ is not necessarily a username.

Well, yes and no.

Technically, it's a mailbox name and there is - USUALLY - a strong, if
not direct, correlation between the mailbox name and the username.

> Today it is
> practically never a username.

That is inconsistent with my experience. In my experience, the mailbox
name is almost always the user name, unless the messaging system
provides a correlation between the mailbox name and a username at some
level.

> 15 years ago it did not have to be
> a username (PMDF supported firstname.lastname back then).

...and even today it does not NEED to be a username, but typically is,
especially in the Windows/Exchange world. 

For example, an LDAP username typically has a direct correlation to the
mailbox name in Exchange in a corporate e-mail system, unless the people
who run the e-mail system have a management mandate to have "e-mail
names" be as "human" as possible, as in "David.Dachtera" vs. "ddach459",
which, of course, instantly makes e-mail unmanageable.

On a former site of mine, management insisted that the e-mail admin.'s
abuse SNADS to the point that every ten-character First Name became a
distribution group name (DGN), and every last name became a Distribution
Element Name (DEN). Thus, my e-mail name in SNADS was DGN=DAVID,
DEN=DACHTERA (DAVID.DACHTERA) instead of, oh, say, DGN=CGOCDC (Chicago
Corporate Data Center), DEN=DDACHTERA (CHCGOCDC.DDACHTERA). My VMS
username was DDACHTERA, which matched my mailbox name in All-in-1.

Naturally every "Christopher" in the company instantly became
"CHRISTOPHE".

Loads o'laughs...

D.J.D.