PHP: Sending huge quantity of emails in batch

Question

Putting aside the disdain from junk marketing I need to send around 15,000 emails to customers. My coworker has tried to send them through php mail loop but obviously it get

Answer 1

No matter how you implement immediate delivery: it'll be a lengthy process that's always subject to interruptions and you can't afford restarting the delivery and sending the same message twice to 5,000 customers.

I believe that a reliable system must use queues. The main script simply adds recipients to a queue and then you have a secondary process that picks items from the queue, get them sent and finally mark them as sent. This secondary process can be launched manually (maybe from the command line) or via cron tab.

I've never used but I have this in my bookmarks: http://ledscripts.com/free/php/phpledmailer