tried to roll my own email server on a .xyz domain...basically a big no go, couple of emails went through, then nothing, just a black hole. Thanks corpos and the safety theatre.
Call me a luddite but if it isn't one of the original big TLDs, a country TLD, or similar, I just don't trust it for anything serious.
In Defender for Exchange (or whatever they call the filter in exchange online these days), there is a checkbox that blocks .xyz and .biz as a bundle. Why those two? dunno, but microsoft especially hates them.