Problem/Motivation
I don't understand this error: Symfony\Component\Mime\Exception\RfcComplianceException: Email "<info@kunstbehoudgroningen.nl>" does not comply with addr-spec of RFC 2822. in Symfony\Component\Mime\Address->__construct() (line 54 of /xxx/drupal/vendor/symfony/mime/Address.php).
info@kunstbehoudgroningen.nl is, in my opinion, a valid email address.