diff --git a/config/environments/production.rb b/config/environments/production.rb
index 971fe022..57ff50a8 100644
--- a/config/environments/production.rb
+++ b/config/environments/production.rb
@@ -85,7 +85,7 @@ Rails.application.configure do
       user_name: ENV.fetch('SMTP_USERNAME', nil),
       password: ENV.fetch('SMTP_PASSWORD', nil),
       authentication: ENV.fetch('SMTP_AUTHENTICATION', 'plain'),
-      enable_starttls_auto: ENV['SMTP_ENABLE_STARTTLS_AUTO'] == 'true'
+      enable_starttls_auto: ENV['SMTP_ENABLE_STARTTLS_AUTO'] != 'false'
     }.compact
   end