I just registered for this forum but had to use another email address than the one I'd preferred, i.e. my yahoo-account, because I got the message that the latter was "banned". I tried to change it later in my profile but, again, it doesn't allow me. Any reason why this could be the case?
Welcome to these forums. We have been having lots of problems with spam-registrations here previously so many email-domains that spammers typically used are banned. I've now removed this ban so you can change your email if you want, but I may need to turn it back on later.