Creating an account with Mendix is the first step to joining Mendix, without an account with Mendix you will not be able to do much such downloading, joining Mendix academy and creating apps.
So it is very important first to create an account with Mendix.
Mendix doesn’t accept third party’s email domains such googele, yahoo Microsoft email domains. So you have to have an email address with a company’s domain name shuch yourname@yourwebsite.com.
from this link you can create an account with Mendix https://signup.mendix.com/link/signup/