SPF List,
I had a thought (yes, I know, the media has been alerted) to reduce
redundant DNS data transfer as regards the migration to the SPF RR
from the TXT RR.
Does it make any sense to add a new option for an SPF record to the
specification that allows for the TXT record to indicate support
exists or does not exist for SPF under the new SPF RR record? For example:
TXT "v=spf1 {all the other stuff normally published} [+|-]spf"
where the trailing "spf" above offers a hint to an MTA that an SPF RR
is also being published. Obviously, the option name need not be
"spf", but could alternately be something like "rr" or even "spfrr",
the point is adding something that tells the software interpreting
the record that the requested answer is available or not available
via the SPF RR record. This might also be valuable for some
publishers to avoid redundant lookups where their DNS implementation
for whatever reason does not or cannot support the new SPF RR record
and thus can supply a clue to avoid the requesting MTA having to do
an extra lookup that is guaranteed to fail - saving everyone a bit of
a headache.
Somewhere down the road, publishers might also want to use this
ability to reduce the amount of traffic from redundant data being
sent by both a TXT RR and SPF RR request. Eventually, just
publishing a TXT "v=spf1 +spf" could be interpreted as, "why yes, we
do publish SPF data, but your answer is found at our SPF RR, so use that".
I just thought it might be nice to have this feature as part of a
proactive plan for the migration away from the TXT SPF record.
Best,
Alan Maitland
WebMaster(_at_)Commerco(_dot_)Net
The Commerce Company - Making Commerce Simple(sm)
http://WWW.Commerco.Com/