The type of an email address
fromString : String -> Maybe EmailAddress
Parse an email address from a String.
Note that this will also convert all the characters to lowercase.
This is done because email addresses are case insensitive.
If the email wasn't converted to all lowercase you could end up with this gotcha Email.fromString a@a.com /= Email.fromString A@a.com
toString : EmailAddress -> String
Render Email to a String