diff --git a/config/environments/development.rb b/config/environments/development.rb
index df0e399..0349434 100644
--- a/config/environments/development.rb
+++ b/config/environments/development.rb
@@ -1,7 +1,7 @@
 require "active_support/core_ext/integer/time"
 
 Rails.application.configure do
-  config.hosts = ['survey-api-staging.nimblehq.co', 'https://survey-api.nimblehq.co']
+  config.hosts = [ENV.fetch('MAILER_DEFAULT_HOST')]
   # Settings specified here will take precedence over those in config/application.rb.
 
   # In the development environment your application's code is reloaded any time
diff --git a/config/environments/production.rb b/config/environments/production.rb
index a292c4b..ba53047 100644
--- a/config/environments/production.rb
+++ b/config/environments/production.rb
@@ -1,6 +1,8 @@
 require "active_support/core_ext/integer/time"
 
 Rails.application.configure do
+  config.hosts = [ENV.fetch('MAILER_DEFAULT_HOST')]
+
   # Settings specified here will take precedence over those in config/application.rb.
 
   # Code is not reloaded between requests.