Unnecessary and deeply concerning bow to the new “king”
Update: position got backed up by an official Proton post on Mastodon, it’s an official Proton statement now. https://mastodon.social/@protonprivacy/113833073219145503
Update 2, plot-twist: they removed this response from Mastodon - seems they realize it exploded into their face!
I don’t know any guide, but deliverability is the biggest concern and it may also not be fully under control. Sometimes IP blocks get blacklisted or deranked and your emails end in spam, and you might not even know that.