Cannot Register, Multiple Failures

I cannot seen to register for GitLab; I’ve tried three different ways.

Firstly, wsing my primary e-mail, the registration form gives an error about the e-mail address domain is not permitted. Considering the captcha and confirmation process, I don’t see why such discrimnatory blocking is used.

Secondly, I created a new e-mail address at ProtonMail and this allowed me to progress to the e-mail confirmation stage, but the confirmation never arrived. I tried to resend the mail four times and checked my spam folder.

Finally, I tried using my GitHub account. That’s what I’m using to submit this topic to the forums. This allowed me to create an account and I see the OAuth “application” authorized on my GitHub account…but I still cannot login to GitLab! I get an error “422”.

Can someone please help me?