Queue ActionMailer e-mails with ar_mailer

ar_mailer is a system that automatically queues outgoing mails from Rails applications (using ActionMailer) by placing them into a special database table, to then be handled by a separate process, ar_sendmail. This could be particularly ideal for systems with mass mailing applications or simply as a method to speed up certain requests in your Rails applications since only a single database write is required rather than waiting for an e-mail to finish sending.