diff --git a/src/main/resources/reference.conf b/src/main/resources/reference.conf
index 6213c40f7..a11d95845 100644
--- a/src/main/resources/reference.conf
+++ b/src/main/resources/reference.conf
@@ -80,26 +80,26 @@ nih {
   # NIH prohibits accounts from free email providers or emails from contries of concern
   # (?i) is case insensitive
   denyEmailPatterns = [
-    "(?i).+@(.+\\.)*126\\..+",
-    "(?i).+@(.+\\.)*163\\..+",
-    "(?i).+@(.+\\.)*aol\\..+",
-    "(?i).+@(.+\\.)*bk\\..+",
-    "(?i).+@(.+\\.)*foxmail\\..+",
-    "(?i).+@(.+\\.)*gmail\\..+",
-    "(?i).+@(.+\\.)*hotmail\\..+",
-    "(?i).+@(.+\\.)*icloud\\..+",
-    "(?i).+@(.+\\.)*inbox\\..+",
-    "(?i).+@(.+\\.)*live\\..+",
-    "(?i).+@(.+\\.)*mail\\..+",
-    "(?i).+@(.+\\.)*mailinator\\..+",
-    "(?i).+@(.+\\.)*outlook\\..+",
-    "(?i).+@(.+\\.)*proton\\..+",
-    "(?i).+@(.+\\.)*qq\\..+",
-    "(?i).+@(.+\\.)*rambler\\..+",
-    "(?i).+@(.+\\.)*sina\\..+",
-    "(?i).+@(.+\\.)*yeah\\..+",
-    "(?i).+@(.+\\.)*yahoo\\..+",
-    "(?i).+@(.+\\.)*yandex\\..+",
+    "(?i).+@(.+\\.)*126\\.[^.]+",
+    "(?i).+@(.+\\.)*163\\.[^.]+",
+    "(?i).+@(.+\\.)*aol\\.[^.]+",
+    "(?i).+@(.+\\.)*bk\\.[^.]+",
+    "(?i).+@(.+\\.)*foxmail\\.[^.]+",
+    "(?i).+@(.+\\.)*gmail\\.[^.]+",
+    "(?i).+@(.+\\.)*hotmail\\.[^.]+",
+    "(?i).+@(.+\\.)*icloud\\.[^.]+",
+    "(?i).+@(.+\\.)*inbox\\.[^.]+",
+    "(?i).+@(.+\\.)*live\\.[^.]+",
+    "(?i).+@(.+\\.)*mail\\.[^.]+",
+    "(?i).+@(.+\\.)*mailinator\\.[^.]+",
+    "(?i).+@(.+\\.)*outlook\\.[^.]+",
+    "(?i).+@(.+\\.)*proton\\.[^.]+",
+    "(?i).+@(.+\\.)*qq\\.[^.]+",
+    "(?i).+@(.+\\.)*rambler\\.[^.]+",
+    "(?i).+@(.+\\.)*sina\\.[^.]+",
+    "(?i).+@(.+\\.)*yeah\\.[^.]+",
+    "(?i).+@(.+\\.)*yahoo\\.[^.]+",
+    "(?i).+@(.+\\.)*yandex\\.[^.]+",
     "(?i).+@(.+\\.)*ecohealthalliance\\.org",
     "(?i).+@(.+\\.)+cn",
     "(?i).+@(.+\\.)+hk",