Sending email can be a bottleneck in your Rails app. Here's a dead simple way of making all your mail be delivered asynchronously.

With the plugin installed, all mail send from Mailer gets put into a table called QueuedMails. Here's my migration to add that table:

class AddQueuedMailTable < ActiveRecord::Migration
  def self.up
    create_table :queued_mails do |t|
      t.column :object,     :text
      t.column :mailer,     :string
    end
  end

  def self.down
    drop_table :queued_mails
  end
end

Now everytime you call

YouMailer.deliver_something(*params)

that mail object will be stored in the QueuedMails table. Just periodically call script/runner from a cron job to process your new mail queue:

"script/runner 'MailQueue.process' -e production"

If you want to bypass the queue just called the deliver_method_name with an exclamation point at the end. Like:

YouMailer.deliver_something!(*params)

WARNING:

This feature to bypass the queue isn't the same way it was done in the original release of this plugin, so it isn't backwards compatible. Not a huge thing to change, and it probably wasn't a very popular thing used by people using this plugin anyways.

Nate, Inkling Inc., http://www.inklingmarkets.com