diff --git a/core/admin/mailu/internal/nginx.py b/core/admin/mailu/internal/nginx.py
index b9cbe879..864f6116 100644
--- a/core/admin/mailu/internal/nginx.py
+++ b/core/admin/mailu/internal/nginx.py
@@ -14,6 +14,7 @@ STATUSES = {
         "imap": "AUTHENTICATIONFAILED",
         "smtp": "535 5.7.8",
         "submission": "535 5.7.8",
+        "lmtp": "535 5.7.8",
         "pop3": "-ERR Authentication failed",
         "sieve": "AuthFailed"
     }),
@@ -21,6 +22,7 @@ STATUSES = {
         "imap": "PRIVACYREQUIRED",
         "smtp": "530 5.7.0",
         "submission": "530 5.7.0",
+        "lmtp": "530 5.7.0",
         "pop3": "-ERR Authentication canceled.",
         "sieve": "ENCRYPT-NEEDED"
     }),
@@ -28,6 +30,7 @@ STATUSES = {
         "imap": "LIMIT",
         "smtp": "451 4.3.2",
         "submission": "451 4.3.2",
+        "lmtp": "451 4.3.2",
         "pop3": "-ERR [LOGIN-DELAY] Retry later",
         "sieve": "AuthFailed"
     }),
diff --git a/towncrier/newsfragments/3696.bugfix b/towncrier/newsfragments/3696.bugfix
new file mode 100644
index 00000000..2ecea51b
--- /dev/null
+++ b/towncrier/newsfragments/3696.bugfix
@@ -0,0 +1 @@
+Include error messages for LMTP