The EmailMatcher can't recognize an email with subject and/or body

I have committed a simple fix.
It can be improved if required by using regex. Also "if (filter_var($string, FILTER_VALIDATE_EMAIL))" can be replaced with something like "\Drupal::service('email.validator')->isValid($string)".
I decided to use explode() instead of preg_replace() because explode() will work faster.

This is a very sensible change! Thanks for reporting and providing the nice implementation!

Automatically closed - issue fixed for 2 weeks with no activity.