I'm working on an application where users have to use a specific email domain to sign up (Either
@b.com. Anything else gets rejected).
In order to prevent my users from going through the form, clicking sign up, and being told they're e-mail is wrong, I'm adding warnings to the e-mail boxes.
Currently, if the user puts in an e-mail on the wrong domain, they get a red warning to the left that says they are using the wrong e-mail, however my boss would like to disable the e-mail confirmation field as well as the sign up button. I think doing both is a little extreme, but I think adding another one would be worth it, but I'm not sure which one to add.
Should I disable the sign up button, the confirm e-mail input field, both, or neither?