Yes and no. Isn’t there an argument that Gmail and Outlook.com (combined with Microsoft 365/Exchange Online), while superficially interoperable, have enough market share that their actions make running other mail providers very difficult in practice?
> Isn’t there an argument that Gmail and Outlook.com (combined with Microsoft 365/Exchange Online), while superficially interoperable, have enough market share that their actions make running other mail providers very difficult in practice?
Yes, there is an argument to be made for that. I personally agree with that viewpoint. But that doesn’t mean arguing against it is “mental gymnastics”. It’s possible for reasonable people to disagree about things.
