diff --git a/lib/rodauth/rails.rb b/lib/rodauth/rails.rb
index c670783..599ea8d 100644
--- a/lib/rodauth/rails.rb
+++ b/lib/rodauth/rails.rb
@@ -10,6 +10,7 @@ class Error < StandardError
     # This allows avoiding loading Rodauth at boot time.
     autoload :App, "rodauth/rails/app"
     autoload :Auth, "rodauth/rails/auth"
+    autoload :Mailer, "rodauth/rails/mailer"
 
     @app = nil
     @middleware = true
diff --git a/lib/rodauth/rails/feature/email.rb b/lib/rodauth/rails/feature/email.rb
index d25fafd..d0c7367 100644
--- a/lib/rodauth/rails/feature/email.rb
+++ b/lib/rodauth/rails/feature/email.rb
@@ -12,20 +12,13 @@ module Email
 
         # Create emails with ActionMailer which uses configured delivery method.
         def create_email_to(to, subject, body)
-          Mailer.create_email(to: to, from: email_from, subject: "#{email_subject_prefix}#{subject}", body: body)
+          Rodauth::Rails::Mailer.create_email(to: to, from: email_from, subject: "#{email_subject_prefix}#{subject}", body: body)
         end
 
         # Delivers the given email.
         def send_email(email)
           email.deliver_now
         end
-
-        # ActionMailer subclass for correct email delivering.
-        class Mailer < ActionMailer::Base
-          def create_email(options)
-            mail(options)
-          end
-        end
       end
     end
   end
diff --git a/lib/rodauth/rails/mailer.rb b/lib/rodauth/rails/mailer.rb
new file mode 100644
index 0000000..c61de1c
--- /dev/null
+++ b/lib/rodauth/rails/mailer.rb
@@ -0,0 +1,9 @@
+module Rodauth
+  module Rails
+    class Mailer < ActionMailer::Base
+      def create_email(options)
+        mail(options)
+      end
+    end
+  end
+end