--- a/wp-includes/pluggable.php
+++ b/wp-includes/pluggable.php
@@ -710,7 +710,7 @@ function wp_mail( $to, $subject, $message, $headers = '', $attachments = array()

         // Build mail data for hooks.
-        $mail_data = compact( 'to', 'subject', 'message', 'headers', 'attachments' );
+        $mail_data = compact( 'to', 'subject', 'message', 'headers', 'attachments', 'embeds' );

         /**
          * Fires after PHPMailer has successfully sent an email.