Backtick in domain is incorrectly considered valid

[Jamesking56]

$validator = new EmailValidator();
$result = $validator->isValid("someone@email`s.com", new RFCValidation());

$result returns true when it should return false, Backticks aren't allowed in the domain portion according to the RFC

[egulias]

Thanks for reporting @Jamesking56 .
Arguably, it is valid in the broader definition of the RFC 5322, see https://tools.ietf.org/html/rfc5322#section-3.4.1 . It is true that regarding RFC1035 backtick is not allowed.
I'll address it, nevertheless, this is a behaviour change since this V2 of the validator follows the broader definition. This will change in V3.