I think the main issue is that google doesn't accept certain senders anymore. As a generic thread about running a mailserver/mail service pops up here often.
That means users are shoveled into about one of 4 "acceptable" providers which have control of the entire market. They demand, full name and usually gender, mobile, alternative email and more.
So you get pushed into their information pipeline to stop "spam".
That means users are shoveled into about one of 4 "acceptable" providers which have control of the entire market. They demand, full name and usually gender, mobile, alternative email and more.
So you get pushed into their information pipeline to stop "spam".