On Thu, Apr 2, 2015 at 6:53 AM, Ted Mittelstaedt <[email protected]> wrote: > > > > On 4/2/2015 3:07 AM, Bill Owens wrote: >> >> On Thu, Apr 2, 2015 at 3:38 AM, Ted Mittelstaedt <[email protected] >> <mailto:[email protected]>> wrote: >> > >> > I guess I don't understand why this is an IPv6 issue. >> > >> > You said: >> > >> > "...we've discovered that there are sporadic failures even when there >> are valid SPF records..."" >> > >> > If there are sporadic failures internally in Microsoft how can they >> > guarantee that those sporadic failures will go away if you change to >> > IPv4? >> >> It's an IPv6 issue because Microsoft has made it their policy to require >> SPF (or DKIM) for mail that arrives over IPv6 transport, and not for >> mail that arrives over IPv4. This particular topic was brought up a few >> months ago: >> https://www.mail-archive.com/[email protected]/msg01549.html >> It's also documented by Microsoft themselves: >> https://technet.microsoft.com/en-us/library/dn720852%28v=exchg.150%29.aspx >> And apparently the MAAWG agrees, for whatever that's worth: >> https://www.m3aawg.org/sites/maawg/files/news/M3AAWG_Inbound_IPv6_Policy_Issues-2014-09.pdf >> >> So yes, I can guarantee that the problem will go away by changing to IPv4. >> > > You said in your original post that they were ALSO losing mail during INTERNAL transfers WITHIN their system. > > If they receive mail via IPv4 and then transfer it from server to server via IPv6 and there is no SPF record it seems to me that the > same problem will happen. You had said this much was already happening.
Yes, because they have our domain marked to require SPF checks. If we were to switch off IPv6, that would no longer be the case. > It just sounds to me like your making excuses for them. > > It sounds like the same problem those sex-trafficked victims have. > Their pimps beat them and they still make excuses for their pimps and > defend them. Thanks for that viewpoint. I'll confine my remarks to the topic of IPv6 and email, though. Bill.
