At 02:09 PM 1/6/97 +0000, Michael C. Berch wrote:
[stuff in terms of rewriting email@example.com to firstname.lastname@example.org]
>Right. But it shouldn't matter what sort of random cruft Pegasus (or
>any other client mailer) sticks in the From: line; when the Netcom
>mail relay processes it, it should rewrite the From: line to a
>canonical form. That's trivial, and most ISPs seem to do that.
They need to do it *carefully*. For example, I'm frequently (as now)
sending mail "From: email@example.com" but actually sending it
from another account "firstname.lastname@example.org", and I *don't* want it
rewritten to show that. People with two or more accounts frequently
do this. (Another header such as "X-Sender:" is added here, so it's
not forged, but mailers won't respond to it either, which is what
I'm not sure that most ISP's do any rewriting rather than just
supplying "From:" when the user's MUA leaves it absent.
>> The solution for them was to use the Pegasus "advanced configuration
>> options" and tell Pegasus what their "From" address is (and to use it
>> in the SMTP envelope), so that Pegasus doesn't auto-generate the
>> From: address.
LISTSERV uses "From:" rather than the SMTP "MAIL FROM". I don't know
about other MLM's.
>It would seem that their support burden would be greatly lessened if
>they just fixed their mail relays to take care of this, instead of
>trying to support every !~@#$% PC mailer out there. But this is
>Netcom we are talking about here, who is not exactly known for their
Well, unfortunately, in terms of the RFC's, nobody is "broken" -- all
"comply" since email@example.com is a replyable address. Thus,
laying blame isn't so clear.
Perhaps the real problem is MLM software which has been assuming that
all messages from the same person will always have the same "From:"
header. Nothing in the RFC's require that. Even slightly clever MLM
software could allow subscriptions of the form:
(I am using regexp notation as in procmail or egrep, not implying that
subscribers need to "see" it). This would match firstname.lastname@example.org,
email@example.com, but not firstname.lastname@example.org, for example.
This would not be an expensive check, since it applies only once per
incoming message to a list, *not* to all the outgoing addresses.