diff --git a/CHANGELOG.md b/CHANGELOG.md
index 37193645..5b844349 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,8 +1,11 @@
 Unreleased Changes
 ------------------
 
+* Issue - Ensure `:ses` or `:sesv2` as ActionMailer configuration.
+
 * Feature - Do not allow `:amazon`, `amazon_sqs`, or `amazon_sqs_async` for SQS active job configuration. Instead use `:sqs` and `:sqs_async`.
 
+
 3.13.0 (2024-06-06)
 ------------------
 
diff --git a/lib/aws/rails/railtie.rb b/lib/aws/rails/railtie.rb
index e94d68e7..0836c3c5 100644
--- a/lib/aws/rails/railtie.rb
+++ b/lib/aws/rails/railtie.rb
@@ -9,7 +9,7 @@ class Railtie < ::Rails::Railtie
                   before: :load_config_initializers do
         # Initialization Actions
         Aws::Rails.use_rails_encrypted_credentials
-        Aws::Rails.add_action_mailer_delivery_method
+        Aws::Rails.add_action_mailer_delivery_method(:ses)
         Aws::Rails.add_action_mailer_delivery_method(:sesv2)
         Aws::Rails.log_to_rails_logger
       end
@@ -25,18 +25,22 @@ class Railtie < ::Rails::Railtie
     end
 
     # This is called automatically from the SDK's Railtie, but can be manually
-    # called if you want to specify options for building the Aws::SES::Client.
+    # called if you want to specify options for building the Aws::SES::Client or
+    # Aws::SESV2::Client.
     #
     # @param [Symbol] name The name of the ActionMailer delivery method to
-    #   register.
+    #   register, either :ses or :sesv2.
     # @param [Hash] client_options The options you wish to pass on to the
     #   Aws::SES[V2]::Client initialization method.
-    def self.add_action_mailer_delivery_method(name = :ses, client_options = {})
+    def self.add_action_mailer_delivery_method(name, client_options = {})
       ActiveSupport.on_load(:action_mailer) do
-        if name == :sesv2
+        case name
+        when :ses
+          add_delivery_method(name, Aws::Rails::SesMailer, client_options)
+        when :sesv2
           add_delivery_method(name, Aws::Rails::Sesv2Mailer, client_options)
         else
-          add_delivery_method(name, Aws::Rails::SesMailer, client_options)
+          raise ArgumentError, "Unknown action mailer delivery method: #{name}"
         end
       end
     end