diff --git a/package-lock.json b/package-lock.json
index 2057a14..3acb721 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -64,7 +64,7 @@
       "dependencies": {
         "acorn": {
           "version": "3.3.0",
-          "resolved": "http://registry.npmjs.org/acorn/-/acorn-3.3.0.tgz",
+          "resolved": "https://registry.npmjs.org/acorn/-/acorn-3.3.0.tgz",
           "integrity": "sha1-ReN/s56No/JbruP/U2niu18iAXo=",
           "dev": true
         }
@@ -747,7 +747,7 @@
       "dependencies": {
         "pify": {
           "version": "2.3.0",
-          "resolved": "http://registry.npmjs.org/pify/-/pify-2.3.0.tgz",
+          "resolved": "https://registry.npmjs.org/pify/-/pify-2.3.0.tgz",
           "integrity": "sha1-7RQaasBDqEnqWISY59yosVMw6Qw=",
           "dev": true
         }
@@ -1164,9 +1164,9 @@
       }
     },
     "nodemailer": {
-      "version": "4.6.8",
-      "resolved": "https://registry.npmjs.org/nodemailer/-/nodemailer-4.6.8.tgz",
-      "integrity": "sha512-A3s7EM/426OBIZbLHXq2KkgvmKbn2Xga4m4G+ZUA4IaZvG8PcZXrFh+2E4VaS2o+emhuUVRnzKN2YmpkXQ9qwA==",
+      "version": "6.4.16",
+      "resolved": "https://registry.npmjs.org/nodemailer/-/nodemailer-6.4.16.tgz",
+      "integrity": "sha512-68K0LgZ6hmZ7PVmwL78gzNdjpj5viqBdFqKrTtr9bZbJYj6BRj5W6WGkxXrEnUl3Co3CBXi3CZBUlpV/foGnOQ==",
       "dev": true
     },
     "number-is-nan": {
@@ -1539,7 +1539,7 @@
     },
     "strip-ansi": {
       "version": "3.0.1",
-      "resolved": "http://registry.npmjs.org/strip-ansi/-/strip-ansi-3.0.1.tgz",
+      "resolved": "https://registry.npmjs.org/strip-ansi/-/strip-ansi-3.0.1.tgz",
       "integrity": "sha1-ajhfuIU9lS1f8F0Oiq+UJ43GPc8=",
       "dev": true,
       "requires": {
diff --git a/package.json b/package.json
index 69a6fe0..629cd5f 100644
--- a/package.json
+++ b/package.json
@@ -30,7 +30,7 @@
     "eslint": "=3.0.0",
     "eslint-config-sparkpost": "1.0.1",
     "mocha": "^5.2.0",
-    "nodemailer": "^4.6.8",
+    "nodemailer": "^6.4.16",
     "sinon": "^7.1.1"
   }
 }