will i still get the email if a person does not put the period after Mr? ([e-mail])?

Answer 1

only if you sign up for both email addresses (which isn't a bad idea!)

Answer 2

If your e-mail address is [e-mail], only mail addressed EXACTLY that way will be delivered. If someone else already has that address, they will receive the mail, not you.

E-Mail systems are pretty stupid, actually. If the address doesn't match up exactly, it's bounced.