[Info-vax] bizarre SMTP problem

[David J Dachtera]

Arne Vajhøj wrote:
> 
> David J Dachtera wrote:
> > 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.
> 
> My experience is that the majority of corporate email use
> firstname.lastname as preferred email address instead of
> username. And that practically no ISP's use username
> for email.

On both Earthlink and Comcast (two of the biggest ISPs in the U.S.), my
username is "djesys" and my primary mailbox name is "djesys". I can
create secondary mailboxes with any valid name that I choose; however,
the primary mailbox name is ALWAYS the same as the subscriber's primary
username.

Likewise DLS (djesys), and AOL (formerly, the biggest ISP in the U.S.,
DJBenedict).

So, not sure how you're gauging "practically no ISP's". I four examples
of the opposite in my case alone, and can cite at least two score more
in my own social circle and extended family.

D.J.D.