diff --git a/lib/Mailer/Methods/ErrorMappers/SMTPMapper.php b/lib/Mailer/Methods/ErrorMappers/SMTPMapper.php
index cda221e1c1..0608e8c8d6 100644
--- a/lib/Mailer/Methods/ErrorMappers/SMTPMapper.php
+++ b/lib/Mailer/Methods/ErrorMappers/SMTPMapper.php
@@ -8,10 +8,25 @@ use MailPoet\Mailer\SubscriberError;
 class SMTPMapper {
   use ConnectionErrorMapperTrait;
 
-  function getErrorFromException(\Exception $e) {
+  /**
+   * @see https://swiftmailer.symfony.com/docs/sending.html
+   * @return MailerError
+   */
+  function getErrorFromException(\Exception $e, $subscriber, $extra_params = []) {
     // remove redundant information appended by Swift logger to exception messages
     $message = explode(PHP_EOL, $e->getMessage());
-    return new MailerError(MailerError::OPERATION_SEND, MailerError::LEVEL_HARD, $message[0]);
+
+    $level = MailerError::LEVEL_HARD;
+    if($e instanceof \Swift_RfcComplianceException) {
+      $level = MailerError::LEVEL_SOFT;
+    }
+
+    $subscriber_errors = [];
+    if(empty($extra_params['test_email'])) {
+      $subscriber_errors[] = new SubscriberError($subscriber, null);
+    }
+
+    return new MailerError(MailerError::OPERATION_SEND, $level, $message[0], null, $subscriber_errors);
   }
 
   function getErrorFromLog($log, $subscriber, $extra_params = []) {
diff --git a/lib/Mailer/Methods/SMTP.php b/lib/Mailer/Methods/SMTP.php
index cb6945f83a..2395594e91 100644
--- a/lib/Mailer/Methods/SMTP.php
+++ b/lib/Mailer/Methods/SMTP.php
@@ -49,7 +49,7 @@ class SMTP {
       $result = $this->mailer->send($message);
     } catch(\Exception $e) {
       return Mailer::formatMailerErrorResult(
-        $this->error_mapper->getErrorFromException($e)
+        $this->error_mapper->getErrorFromException($e, $subscriber, $extra_params)
       );
     }
     if($result === 1) {
diff --git a/tests/unit/Mailer/Methods/ErrorMappers/SMTPMapperTest.php b/tests/unit/Mailer/Methods/ErrorMappers/SMTPMapperTest.php
index 90b694147a..62785c1f32 100644
--- a/tests/unit/Mailer/Methods/ErrorMappers/SMTPMapperTest.php
+++ b/tests/unit/Mailer/Methods/ErrorMappers/SMTPMapperTest.php
@@ -2,6 +2,7 @@
 namespace MailPoet\Test\Mailer\Methods\ErrorMappers;
 
 use MailPoet\Mailer\Mailer;
+use MailPoet\Mailer\MailerError;
 use MailPoet\Mailer\Methods\ErrorMappers\SMTPMapper;
 
 class SMTPMapperTest extends \MailPoetTest {
@@ -18,9 +19,17 @@ class SMTPMapperTest extends \MailPoetTest {
       . 'Log data:' . PHP_EOL
       . '++ Starting Swift_SmtpTransport' . PHP_EOL
       . '!! Connection could not be established with host localhost [Connection refused #111] (code: 0)';
-    $error = $this->mapper->getErrorFromException(new \Exception($message));
+    $error = $this->mapper->getErrorFromException(new \Exception($message), 'john@rambo.com');
     expect($error->getMessage())
       ->equals('Connection could not be established with host localhost [Connection refused #111]');
+    expect($error->getLevel())->equals(MailerError::LEVEL_HARD);
+    expect($error->getSubscriberErrors()[0]->getEmail())->equals('john@rambo.com');
+  }
+
+  function testItCreatesSoftErrorForInvalidEmail() {
+    $message = 'Invalid email';
+    $error = $this->mapper->getErrorFromException(new \Swift_RfcComplianceException($message), 'john@rambo.com');
+    expect($error->getLevel())->equals(MailerError::LEVEL_SOFT);
   }
 
   function testItCanProcessLogMessageWhenOneExists() {