Can’t verify email

Hello, I just used, what I thought to be, my school email to utilize the student discount. But when asked to verify it, I wasn’t receiving any emails. Upon further inspection, I typed the wrong email. The original email that I used was (insert email here)@pasadena.edu, but in reality, the email is (insert email here) @5117094.pasadena.edu. When attempting to change it to (insert email here) @5117094.pasadena.edu, it won’t allow me because the email isn’t “valid”. I am unsure if the @5117094. Is effecting the emails validity.  Please help.