Since the discussion of solutions and implementation details seems to be full-speed forward, I would like to wrap up the earlier steps. Here is what I have at http://open-mail.org/Forwarding.html. The only thing new is Problem R. This goes well beyond the specifics of forwarding, but I thought it would be good to include in our list. In devising a solution to the Forwarding Problem, we should do our best to have it solve the larger problem as well.
Statement of Forwarding Problems
Problem S - To technologies like SPF, messages forwarded without re-writing the Return Address appear to be forgeries.
Problem K - Forwarders will accumulate "bad karma" when they innocently pass on spam to a downstream Agent without prior arrangement, or with arrangements that are mistakenly ignored.
Problem B - Mail may be lost when a Receiver accepts a message without authenticating the Return Address and a downstream Agent rejects it.
(still needing discussion):
Problem P - Recipients have difficulty keeping track of and updating their forwarding arrangements.
Problem R - The reliability of the global email system is so bad that users cannot be confident of delivery unless there is prior arrangement between Agents at the Border of the sending and receiving networks.
Requirements for Solution to Forwarding Problems
1) No cost or risk to Agents on Sender's side
2) Small cost or risk to Agents on Recipient's side
3) No lost mail
4) Effective
5) Minimum vulnerability to new attacks
6) At every stage of adoption, benefits must exceed costs to each Agent
that must take some action.
(still needing discussion):
7) Forwarder authentication must be resolved before the DATA command.
Possible Solutions
see http://open-mail.org/Forwarding.html Have I forgotten anything?
-- Dave
-------------------------------------------
Sender Policy Framework: http://www.openspf.org
Archives: http://v2.listbox.com/member/archive/735/=now
RSS Feed: http://v2.listbox.com/member/archive/rss/735/
Modify Your Subscription: http://v2.listbox.com/member/?member_id=1311532&id_secret=94615371-eebf41
Powered by Listbox: http://www.listbox.com
Statement of Forwarding Problems
Problem S - To technologies like SPF, messages forwarded without re-writing the Return Address appear to be forgeries.
Problem K - Forwarders will accumulate "bad karma" when they innocently pass on spam to a downstream Agent without prior arrangement, or with arrangements that are mistakenly ignored.
Problem B - Mail may be lost when a Receiver accepts a message without authenticating the Return Address and a downstream Agent rejects it.
(still needing discussion):
Problem P - Recipients have difficulty keeping track of and updating their forwarding arrangements.
Problem R - The reliability of the global email system is so bad that users cannot be confident of delivery unless there is prior arrangement between Agents at the Border of the sending and receiving networks.
Requirements for Solution to Forwarding Problems
1) No cost or risk to Agents on Sender's side
2) Small cost or risk to Agents on Recipient's side
3) No lost mail
4) Effective
5) Minimum vulnerability to new attacks
6) At every stage of adoption, benefits must exceed costs to each Agent
that must take some action.
(still needing discussion):
7) Forwarder authentication must be resolved before the DATA command.
Possible Solutions
see http://open-mail.org/Forwarding.html Have I forgotten anything?
-- Dave
-------------------------------------------
Sender Policy Framework: http://www.openspf.org
Archives: http://v2.listbox.com/member/archive/735/=now
RSS Feed: http://v2.listbox.com/member/archive/rss/735/
Modify Your Subscription: http://v2.listbox.com/member/?member_id=1311532&id_secret=94615371-eebf41
Powered by Listbox: http://www.listbox.com