Upgraded app to Laravel 5.7

app/Config/mail.php

@@ -46,4 +46,10 @@ return [
         ],
     ],
 
+    // Log Channel
+    // If you are using the "log" driver, you may specify the logging channel
+    // if you prefer to keep mail messages separate from other log entries
+    // for simpler reading. Otherwise, the default channel will be used.
+    'log_channel' => env('MAIL_LOG_CHANNEL'),
+
 ];