I dont think so @raf. I can specify my IP's hostname to t-online.de too. On Fri, Dec 10, 2021 at 12:34 PM raf <post...@raf.org> wrote:
> On Tue, Dec 07, 2021 at 07:55:54PM +0800, Piper H <pott...@gmail.com> > wrote: > > > I sent an email from my t-online.de account to gmail. > > Gmail shows SPF pass by best guessing: > > > > Received-SPF: pass (google.com: best guess record for domain of > > x...@t-online.de designates 194.25.134.18 as permitted sender) > > client-ip=194.25.134.18; > > > > And t-online.de has no SPF setup for which you can check from their > domain. > > So what's the best guess record by google? > > > > Thanks in advance. > > Piper > > Just guessing of course, but it's probably the fact that > the host name of 194.25.134.18 is mailout04.t-online.de > whose parent domain (t-online.de) matches sender domain. > They might also accept the sender domain's MX hosts, regardless > of their domain name. > > cheers, > raf > >
