Why? Why? Why? Your local SMTP-based Mail Delivery Agent (MDA) can be configured to to deliver mail directly, or to forward to another host, a practice called

Why? Why? Why? Your local SMTP-based Mail Delivery Agent (MDA) can be configured to to deliver mail directly, or to forward to another host, a practice called Smarthosting, and let the smart host deliver all the mail. So instead of installing a new queueing system, use the one that 's already there. Deliver your mail to the local MDA (e.g. open a pipe to sendmail), and let a time-tested mail queuing system do the job that it was designed to do.