diff --git a/data/codes/451.json b/data/codes/451.json
index 494e97c2..b7b94292 100644
--- a/data/codes/451.json
+++ b/data/codes/451.json
@@ -67,6 +67,13 @@
           "severity": 3,
           "description": "Outlook has determined that the sending IP address has a low reputation, so messages are now temporarily rejected. See Microsoft's documentation on how to determine the source of this poor reputation and how to improve deliverability.",
           "links": []
+        },
+        {
+          "status": "4.7.651",
+          "response": "451 4.7.651 The mail server [x.xx.xx.xx] has been temporarily rate limited due to IP reputation. For e-mail delivery information, see https://postmaster.live.com (S3114) [#.prod.outlook.com #]",
+          "severity": 3,
+          "description": "Outlook has determined that the sending IP address has a low reputation, so messages are now temporarily rejected. See Microsoft's documentation on how to determine the source of this poor reputation and how to improve deliverability.",
+          "links": []
         }
       ]
     },