Checks whether the specified email address is well-formatted.
public static function email ($email)
A string value that specifies the email name to check.
A boolean which is true if the email name is well-formatted, false otherwise.
A valid email name should have the following format:
email_name> part should be at least 1 character long (it shouldn't be missing), and it can contain Latin letters, digits, dots, '_' (underscore), '+' and '-' (hyphen) characters. It should begin with a Latin letter, a digit, an underscore, or a hyphen.
domain> part should be formatted as
label>[.<label>[…]], where a label is a block of 63 characters or less, beginning with a Latin letter and composed of Latin letters (A-Z, a-z), digits (0-9) and '-' (hyphen) characters.