Re: Tangential rant - there - I feel better :-)
Had this happen to me, and was able to solve it by adding a SPF entry to my domain's DNS settings.
2 publicly visible posts • joined 16 Apr 2020
A&A are where I headed post Demon, and I’ve not regretted it. Well worth the price to have a hassle free connection and all the configuration your geek heart could desire.
But still, after 23 years of having that demon email subdomain, I’m going to be a little bit sad to bid it farewell. Plus, of course, it’s a pain in the nethers to track down all those people and companies who still use it to get in touch with me.