diff --git a/config/environments/production.rb b/config/environments/production.rb
index 1404242..bcab0d9 100644
--- a/config/environments/production.rb
+++ b/config/environments/production.rb
@@ -135,7 +135,8 @@ Rails.application.configure do
   config.action_mailer.delivery_method = :smtp
   config.action_mailer.smtp_settings = {
     address: 'postfix',
-    domain: ENV.fetch('SUTTY', 'sutty.nl')
+    domain: ENV.fetch('SUTTY', 'sutty.nl'),
+    enable_starttls_auto: false
   }
   config.action_mailer.default_options = { from: ENV['DEFAULT_FROM'] }