ietf-mxcomp
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Re: consensus call on pra/mailfrom deployment and versioning/scope

2004-09-08 08:45:28

On Wed, Sep 08, 2004 at 08:13:20AM -0700, Rand Wacker wrote:
| 
| In particular, there is nothing in the current drafts that explain how to
| modify messages or envelopes to allow forwarding/mail list/mx backup
| operation...and I'm really hoping you're not suggesting we simply bring
| SRS in to the fold.
| 

If we specify that spf/HELO and spf/SUBMITTER always
override spf/MAIL-FROM, then there is no need for SRS.

For example, at the envelope level only, given Alice sending
mail to Bob who forwards to Robert,

Step 1:
  HELO alice.mta
  MAIL FROM:<alice>
  RCPT TO:<bob>
  DATA
    From: <alice>

Step 2:
  HELO bob.mta
  MAIL FROM:<alice> SUBMITTER=<bob>
  RCPT TO:<robert>
  DATA
    Resent-From: <bob>

At step 2, the receiver can apply spf/HELO tests (or SPF
Lite or CSV or even IP based whitelisting) to bob.mta, and
approve the forwarder based on that.

The receiver can also apply spf/SUBMITTER tests to <bob>,
and approve the forwarder based on that.

Whether the receiver trusts the forwarder through a global
mechanism such as trusted-forwarder.org, or through a local
whitelist of known forwarders, or simply wishes to apply an
open-by-default policy or a closed-by-default policy, can be
up to them.

I predict that commercial forwarding services will do SRS
anyway.


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