diff --git a/Gemfile.lock b/Gemfile.lock
index 3e7524c..10972b4 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -114,6 +114,7 @@ GEM
     marcel (1.0.2)
     matrix (0.4.2)
     method_source (1.0.0)
+    midi-smtp-server (3.0.2)
     mini_mime (1.1.2)
     mini_portile2 (2.6.1)
     minitest (5.15.0)
@@ -246,6 +247,7 @@ DEPENDENCIES
   haml-rails (~> 2.0)
   jbuilder (~> 2.7)
   listen (~> 3.3)
+  midi-smtp-server
   puma (~> 5.0)
   rack-mini-profiler (~> 2.0)
   rails (~> 6.1.4, >= 6.1.4.4)