3 files changed, 13 insertions, 2 deletions
diff --git a/actionmailer/lib/action_mailer/base.rb b/actionmailer/lib/action_mailer/base.rb
index aea2498d4d..f34a9bae47 100644
--- a/actionmailer/lib/action_mailer/base.rb
+++ b/actionmailer/lib/action_mailer/base.rb
@@ -1,5 +1,6 @@
 require 'active_support/core_ext/class'
 require 'mail'
+require 'action_mailer/tmail_compat'
 
 module ActionMailer #:nodoc:
   # Action Mailer allows you to send email from your application using a mailer model and views.
@@ -149,7 +150,7 @@ module ActionMailer #:nodoc:
   #
   #       part "text/plain" do |p|
   #         p.body = render_message("signup-as-plain", :account => recipient)
-  #         p.transfer_encoding = "base64"
+  #         p.content_transfer_encoding = "base64"
   #       end
   #     end
   #   end
diff --git a/actionmailer/lib/action_mailer/test_case.rb b/actionmailer/lib/action_mailer/test_case.rb
index 445abd0b89..e8632d4559 100644
--- a/actionmailer/lib/action_mailer/test_case.rb
+++ b/actionmailer/lib/action_mailer/test_case.rb
@@ -1,5 +1,5 @@
 require 'active_support/test_case'
-require 'mail'
+require 'action_mailer/base'
 
 module ActionMailer
   class NonInferrableMailerError < ::StandardError
diff --git a/actionmailer/lib/action_mailer/tmail_compat.rb b/actionmailer/lib/action_mailer/tmail_compat.rb
index cacd79be27..2fd25ff145 100644
--- a/actionmailer/lib/action_mailer/tmail_compat.rb
+++ b/actionmailer/lib/action_mailer/tmail_compat.rb
@@ -6,5 +6,15 @@ module Mail
       content_type(*args)
     end
     
+    alias :old_transfer_encoding :transfer_encoding
+    def transfer_encoding(value = nil)
+      if value
+        STDERR.puts("Message#transfer_encoding is deprecated, please call Message#content_transfer_encoding with the same arguments.\n#{caller}")
+        content_transfer_encoding(value)
+      else
+        old_transfer_encoding
+      end
+    end
+    
   end
 end
 \ No newline at end of file