Unable to create new accounts in the forum

Hi guys, I'm a patient currently undergoing recovery, I am here with 7 other patients who want to post in forum but their accounts are not being created, specifically when they give their email id, no verification mail comes from the forum. I had an older account so it's working, can anyone suggest what to do?

Advise them not to use GMAIL - if they are.

Try to use a university email, or something more sophisticated.

Stop trying to register with a free proxy.