diff --git a/Gemfile b/Gemfile
index ae75ce9..31294a7 100644
--- a/Gemfile
+++ b/Gemfile
@@ -4,7 +4,7 @@ source 'https://rubygems.org/'
 
 # App Stack
 gem 'json',              '~> 2.3'
-gem 'net-smtp',          '~> 0.3.1'
+gem 'net-smtp',          '~> 0.3.3'
 gem 'passenger',         '~> 6.0'
 gem 'pony',              '~> 1.13'
 gem 'prometheus-client', '~> 2.1'
diff --git a/Gemfile.lock b/Gemfile.lock
index 5505b6b..f5b5fc1 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -4,7 +4,6 @@ GEM
     ansi (1.5.0)
     ast (2.4.2)
     builder (3.2.4)
-    digest (3.1.0)
     json (2.6.2)
     mail (2.7.1)
       mini_mime (>= 0.1.1)
@@ -19,10 +18,8 @@ GEM
       ruby2_keywords (~> 0.0.1)
     net-protocol (0.1.3)
       timeout
-    net-smtp (0.3.1)
-      digest
+    net-smtp (0.3.3)
       net-protocol
-      timeout
     parallel (1.22.1)
     parser (3.2.0.0)
       ast (~> 2.4.1)
@@ -77,7 +74,7 @@ DEPENDENCIES
   json (~> 2.3)
   minitest (~> 5.14, >= 5.14.4)
   minitest-reporters (~> 1.4, >= 1.4.3)
-  net-smtp (~> 0.3.1)
+  net-smtp (~> 0.3.3)
   passenger (~> 6.0)
   pony (~> 1.13)
   prometheus-client (~> 2.1)