On Thu, 17 Mar 2005, Todd Herr wrote:
The problem with our pursuing this angle right now is the fact
that our AUP does not prohibit servers being run in customer
space at present. We do not require that customers relay their
outbound email, even email from their @foo.rr.com address,
through our SMTP servers. (We also do not require that mail being
relayed through our SMTP servers be from addresses ending in
@foo.rr.com.) This would mean that we'd have to have a
single DNS zone with something like 4.5 or so million records in
it; large zones such as that do not transfer well between
servers. (I don't see wildcarding as an option here; would open
us to a DoS attack on the servers hosting the _spf.rr.com zone,
and would be the equivalent of +all, wouldn't it?)
I think the SPF for rr.com, as currently published, best meets
our needs. Our customers send email from sub-domains of rr.com
(each of which has its own SPF record), and the record as it
stands best communicates the information that we need to
communicate regarding the locations of our Road Runner-managed
SMTP servers.
You do realize that foo.rr.com is not the same as rr.com and needs
its own record (which if you want can be redirect to main one by
means of spf), right? Also each actual mail server should also
have its own spf record and those should be specific (they are used
for HELO checks).
--
William Leibzon
Elan Networks
william(_at_)elan(_dot_)net