Unluckily, the thread started by John is not a "thread gone mad", or at
least I don't think it is. The underlying views can be summarized as one of
a. SPF is a bloodily stupid idea that adds to user inconvenience without
much gain to the net as whole. So to prevent SPF from gaining grounds,
Debian should actively not implement anything to make sure mails from
SPF enabled sites to actually get delivered. Then users of SPF will
one day understand how stupid SPF actually is.
b. SPF is a good idea, and Debian should support it even when very few
others are using SPF. So it really should implement SRS to make sure
sites with SPF enabled, and users with who filter mails based on SPF
rules, will be served nicely. Debian should itself publish SPF records
as well.
c. We don't know whether SPF is a good idea, and if enough people do use
it, we should not bar them from access to the Debian list. So even if
Debian might not implement SPF (i.e., not publish a SPF record in the
Debian DNS server), it should implement at least SRS to make sure other
users of SPF is served nicely.
The result of the discussion (whether a or b/c) do directly influence the
action to take.