Add blacklist to Mailer [MAILPOET-2176]

lib/Mailer/Methods/ErrorMappers/PHPMailMapper.php

@@ -7,8 +7,11 @@ use MailPoet\Mailer\SubscriberError;
 use MailPoet\WP\Functions as WPFunctions;
 
 class PHPMailMapper {
+  use BlacklistErrorMapperTrait;
   use ConnectionErrorMapperTrait;
 
+  const METHOD = Mailer::METHOD_PHPMAIL;
+
   function getErrorFromException(\Exception $e, $subscriber) {
     $level = MailerError::LEVEL_HARD;
     if (strpos($e->getMessage(), 'Invalid address') === 0) {