Re: A request to all mail admins

From: Hubert Chan (
Date: 08/28/03

Date: Thu, 28 Aug 2003 12:48:43 -0400

>>>>> "Jem" == Jem Berkes <> writes:


Jem> One suggestion that has been well formulated is the RMX resource
Jem> record in DNS. A domain owner would list all mail servers
Jem> authorized to send mail on behalf of the domain name. Mail servers
Jem> that support RMX checking would do a type=RMX lookup on the domain
Jem> name in the From field, and get back a list of authorized relay IPs
Jem> for the domain. Then it's a simple check; is the connecting mail
Jem> relay one of these authorized IPs?

I don't like this. I have more than a handfull of email addresses,
used for different purposes. Right now, all of my outgoing mail gets
sent through a single SMTP server. If this scheme caught on, I would
have to set up my mail client to use a different SMTP server for each

As it stands, I can also let a friend use my MUA to send a mail, and
change the From: header to his address, if he cannot access his own MUA
for any reason (e.g. he's away from his computer) and needs to send a
mail. This would not be possible under the proposed scheme.

I'm sure there are a dozen other things that would break.

What would make more sense, I think, is to have another header,
"Sent-From" (is that already a standard header?), that indicates the
account the mail was sent from, and do RMX checking on that. If the
"Sent-From" header does not exist, fall back to the "From" header.

Hubert Chan <> -
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