diff --git a/subject_spam.map b/subject_spam.map
index 40fd547..6eecd4b 100644
--- a/subject_spam.map
+++ b/subject_spam.map
@@ -10,3 +10,6 @@
 /email storage space/i
 /Roundcube Email Support/i
 /Authenticate Your Email Address/i
+/^Action required:\s*Kindly save billing PDF/i
+/Kindly save billing PDF/i
+/PDF Acknowledgement/i