diff --git a/functions/package-lock.json b/functions/package-lock.json
index e969fdc..111451b 100644
--- a/functions/package-lock.json
+++ b/functions/package-lock.json
@@ -1517,9 +1517,9 @@
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     "nodemailer": {
-      "version": "6.3.1",
-      "resolved": "https://registry.npmjs.org/nodemailer/-/nodemailer-6.3.1.tgz",
-      "integrity": "sha512-j0BsSyaMlyadEDEypK/F+xlne2K5m6wzPYMXS/yxKI0s7jmT1kBx6GEKRVbZmyYfKOsjkeC/TiMVDJBI/w5gMQ=="
+      "version": "6.4.16",
+      "resolved": "https://registry.npmjs.org/nodemailer/-/nodemailer-6.4.16.tgz",
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@@ -1540,7 +1540,8 @@
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+      "optional": true
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@@ -1652,6 +1653,7 @@
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@@ -1661,6 +1663,7 @@
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@@ -1671,6 +1674,7 @@
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+          "optional": true,
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@@ -1682,6 +1686,7 @@
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+          "optional": true,
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@@ -1917,6 +1922,7 @@
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       "resolved": "https://registry.npmjs.org/stream-events/-/stream-events-1.0.5.tgz",
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+      "optional": true,
       "requires": {
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       }
@@ -1949,7 +1955,8 @@
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       "resolved": "https://registry.npmjs.org/stubs/-/stubs-3.0.0.tgz",
-      "integrity": "sha1-6NK6H6nJBXAwPAMLaQD31fiavls="
+      "integrity": "sha1-6NK6H6nJBXAwPAMLaQD31fiavls=",
+      "optional": true
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     "teeny-request": {
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@@ -2127,7 +2134,8 @@
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       "resolved": "https://registry.npmjs.org/xdg-basedir/-/xdg-basedir-4.0.0.tgz",
-      "integrity": "sha512-PSNhEJDejZYV7h50BohL09Er9VaIefr2LMAf3OEmpCkjOi34eYyQYAXUTjEQtZJTKcF0E2UKTh+osDLsgNim9Q=="
+      "integrity": "sha512-PSNhEJDejZYV7h50BohL09Er9VaIefr2LMAf3OEmpCkjOi34eYyQYAXUTjEQtZJTKcF0E2UKTh+osDLsgNim9Q==",
+      "optional": true
     },
     "xtend": {
       "version": "4.0.2",
diff --git a/functions/package.json b/functions/package.json
index 36f5ac9..ffb6286 100644
--- a/functions/package.json
+++ b/functions/package.json
@@ -15,7 +15,7 @@
     "@google-cloud/pubsub": "^1.1.5",
     "firebase-admin": "^8.0.0",
     "firebase-functions": "^3.1.0",
-    "nodemailer": "^6.3.1",
+    "nodemailer": "^6.4.16",
     "request-digest": "^1.0.13"
   },
   "devDependencies": {