diff --git a/notifier/notify.py b/notifier/notify.py
index 7a60fe06..72cb2143 100644
--- a/notifier/notify.py
+++ b/notifier/notify.py
@@ -25,7 +25,12 @@
     EmailAddresses,
     LocalConfig,
 )
-from notifier.wikidot import Wikidot, NotLoggedIn, RestrictedInbox
+from notifier.wikidot import (
+    Wikidot,
+    NotLoggedIn,
+    RestrictedInbox,
+    BlockedInbox,
+)
 
 logger = logging.getLogger(__name__)
 
@@ -455,7 +460,7 @@ def remove_error_tags_from_user() -> None:
         try:
             wikidot.send_message(user["user_id"], subject, body)
         except RestrictedInbox:
-            # If the inbox is restricted, inform the user
+            # If the inbox is restricted to contacts only, inform the user
             logger.debug(
                 "Aborting notification %s",
                 {
@@ -466,6 +471,18 @@ def remove_error_tags_from_user() -> None:
             )
             add_error_tag_to_user("restricted-inbox", post_count)
             return False, 0
+        except BlockedInbox:
+            # If the inbox is blocked to all users, inform the user
+            logger.debug(
+                "Aborting notification %s",
+                {
+                    "for user": user["username"],
+                    "in channel": channel,
+                    "reason": "blocked Wikidot inbox",
+                },
+            )
+            add_error_tag_to_user("blocked-inbox", post_count)
+            return False, 0
         # This user has fixed the above issue, so remove error tags
         remove_error_tags_from_user()
 
diff --git a/notifier/wikidot.py b/notifier/wikidot.py
index 7323aefe..bc993682 100644
--- a/notifier/wikidot.py
+++ b/notifier/wikidot.py
@@ -50,8 +50,12 @@ class ThreadNotExists(Exception):
 
 
 class RestrictedInbox(Exception):
-    """Indicates that a user could not receive a Wikidot PM because their
-    inbox is restricted."""
+    """Indicates that a user could not receive a Wikidot PM because their inbox
+    is restricted to contacts only."""
+
+
+class BlockedInbox(Exception):
+    """Indicates that a user has blocked incoming PMs from all users."""
 
 
 class NotLoggedIn(Exception):
@@ -189,7 +193,7 @@ def module(
             and response["message"]
             == "This user does wish to receive private messages."  # [sic]
         ):
-            raise RestrictedInbox
+            raise BlockedInbox
         if (
             response["status"] == "no_permission"
             and response["message"]