[sossles]

I have an email forwarder on my personal domain that forwards to my gmail address, and gmail lets me send email as if it were coming from that address. Seems like it's the same result, and they're not blocking that.

[lmm]

They've been gradually making it more difficult (you now have to use a backdoor route with a machine access token if you want to register a new sending address).

[anty]

Gmail quietly drops forwarded mails sometimes. They don't put them into the spam directory, either.