On 11/3/2014 3:51 AM, Matija Grabnar wrote:
On 11/03/2014 01:52 AM, Lyle Giese wrote:
If the provider won't or is unable to provide reverse for the IPv6
static address you have, it will be sub-optimal for you to continue
to advertise and/or use the IPv6 address for SMTP.
It's all part of the 'prove it's not a dynamic ip address' and part
of the 'proper reverse DNS provides some level of
authority/delegation to use that ip address for legit SMTP usage'.
My SPF record does exactly that: it provides a level of authority for
that particular host to send mail for my domain.
In a much better, finer grained delegation, since a PTR maps to a
single domain, while a SPF specifies exactly *which* domains permit
that particular host to send mail.
The "need a PTR" requirement was created back when SPF was not even a
glint in anybody's eye. While I would prefer to have PTR records for
all my hosts, I don't agree having no PTR merits a clear rejection of
a mail with a valid SPF record for the host.
On the other hand, their server/their rules. You need to be aware of
their rules if you want to send email to them abide by them as best you can.
Old habits die hard as we all know in the email world.
Lyle Giese
LCR Computer Services, Inc.
