Re: Email Subaddressing

[Bart Schaefer <[e-mail]>]

On Aug 3,  8:24am, D. J. Bernstein wrote:
} Subject: Re: Email Subaddressing
}
} This is getting tiresome. Do you know what ``specific example'' means?

A specific example is not relevant.  I'm not asking anyone to give me
"technical support" with my existing situation; I'd certainly not ask
that of someone with your attitude.

The question is not "what can I do with my current ISPs?"

The question is "how can I avoid having to do something different every
time I get a new ISP?" and secondarily "how could I write a program to
help other people do the same thing regardless of their ISP?"

} > So it can put the right ones in the Reply-To and/or From headers
} 
} Why do you want to do that?

Think of the subaddresses as sender-supplied keywords that respondents
automatically include in their replies.  When I send a message for reason
"X", I want the reply address to have a subaddress of "X".  Then I know
that when I get back a message with "X" in the address, the sender got
my address however indirectly from my original with "X" in it.

Ideally, I'd make up each new "X" on the fly, without having to tell the
LDA or MTA anything about it, yet the response would still end up in the
primary address mailbox.  I can do this with, for example, sendmail 8.x
with the procmail local delivery agent option included in the .cf.

Less ideal would be that I have to tell the LDA and/or MTA about "X", in
which case it would be nice if I could tell every LDA or MTA exactly the
same thing and have it understood in the same way.

Since I'd like to invent "X" on the fly, I'd like to limit the number of
variables imposed by the domain to the right of the "@".  A reasonable
limitation seems to me to be either "supports this and does so the same
way as every other domain that supports it" vs. "doesn't support it."

I can certainly treat all existing MTAs this way, by lumping everybody
who employs a different scheme into the "doesn't" camp, but I'd prefer
to increase the number of "supports it" domains.

If you really can't grasp that without a specific example:  Suppose I
send a message with "schaefer+party-4-july" in the From field local-part.
Now I can filter the responses on "party-4-july".  But in order to do
that, I had to know that "+" is a separator and "-" is not.

} > based on which ISP I'm sending through.
} 
} Why do you want to do that?

Actually, I don't want to do that, but I have no choice when the syntax
for using subaddresses differs from one ISP to the next.

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com