Re: [swinog] hotmail issues since 18/1 ?

Gregor Riepl wrote:

...

It is truly weird. Using the same sender and same path, one email to "some.user@hotmail.com" is accepted, another to "postmaster@hotmail.com" is rejected.

They are probably ramping up rejection rates slowly, as suggested here: https://dmarc.org/overview/

After I filed a support request with Microsoft, they got back to me fairly quickly and said one of our IP-ranges was "a candidate for mitigation". No other explanation offered. I don't see this being a dmarc issue at all, but some sort of internal M$ "reputation list".

Thanks for everyone's suggestions!