[Info-vax] bizarre SMTP problem

[Michael Moroney]

"Bob Eager" <rde42 at spamcop.net> writes:

>On Fri, 10 Apr 2009 01:58:22 UTC, "Steven Underwood" 
><nobody at spamcop.net> 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.
>> > -- 
>> > Bob Eager
>> >
>> 
>> 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. 

>I've come across at least two ISPs where plussed addressing is used to 
>specify multiple mailboxes, of the form account+mailbox. Not that I like
>it...

"Plussed" mailboxes as a way of creating sub-mailboxes has been around for
a while.  Not too heavily used.  As a spamfighting tool it's not too useful
since it's too easy for a spammer to figure out that if foo+bar at example.com
is a valid but tagged email address, foo at example.com is valid as well,
but not tagged.