README.rdoc in adzap-ar_mailer-2.1.8 vs README.rdoc in adzap-ar_mailer-2.1.9

@@ -116,9 +116,67 @@
 If you are on Ruby <= 1.8.6, then the TLS patch included in this plugin will
 be loaded, so you don't need another TLS plugin to add the capability. This
 patch allows you to explicit set if the server supports TLS by setting the
 :tls option to true in your smtp_settings.
 
+
+=== EXPERIMENTAL: Minimal environment loading
+
+The biggest downside to using ar_mailer is that it loads the entire Rails app
+into memory. For larger apps this can be just a whole lot of wasted memory
+given all you need is to access the email table and mailer settings. We can
+get around this using a few conventions and save around 50% or more of the
+memory used when loading the full app.
+
+Loading the database is not much of a problem since the config sits in its own
+yaml which is easy to load in isolation from the app. The mailer settings are
+trickier since they are usually in the environment file which depends on loading
+the Railties system and therefore the whole app.
+
+To workaround for this we need to put all the SMTP settings in a yaml config
+file like the database settings. Like so
+
+in config/email.yml
+
+  development:
+    domain: example.com
+    address: smtp.example.com
+    port: 25
+
+  production:
+    domain: example.com
+    address: smtp.example.com
+    port: 25
+
+You can still have ActionMailer settings in each environment file but just be sure
+they don't override these SMTP settings. The other settings aren't needed when
+running ar_sendmail since they only apply to the generation of an email which has
+already happened inside the running application.
+
+To avoid duplication of these settings you need to have an initializer which will
+will read the same config file and load these settings. This is in case you switch
+back the normal environment loading. Keeping the email settings here is good idea,
+since just the like the database, they are external connection settings being stored
+in the config folder.
+
+The initializer in config/initializers/action_mailer.rb:
+
+  config_file = "#{Rails.root}/config/email.yml"
+  mailer_options = YAML::load(ERB.new(IO.read(config_file)).result)
+  if mailer_options[Rails.env]
+    ActionMailer::Base.smtp_settings = mailer_options[Rails.env].symbolize_keys
+  end
+
+At the moment if you are using a database driver that doesn't come with Rails, the gem
+will need to be installed on the target system.
+
+Now to run ar_sendmail with minimal environment we do:
+
+  ar_sendmail -e production -c /path/to/app --minimal
+
+If you have any troubles or find any bad assumptions in the minimal set up let me know.
+
+
 === Help
 
 See ar_sendmail -h for options to ar_sendmail.
 
 NOTE: You may need to delete an smtp_tls.rb file if you have one lying