Strategy For Scheduling Email Alerts in PHP

Strategy For Scheduling Email Alerts in PHP

I'm writing a PHP project in Laravel. The admin can queue email alerts to
be sent at a specific date/time. The natural choice was to use Laravel's
Queue class with Beanstalkd (Laravel uses Pheanstalk internally).
However, the admin can choose to reschedule or delete email alerts that
have not yet been sent. I could not find a way yet to delete a specific
task so that I can insert a new one with the new timing.
What is the usual technique to accomplish something like this? I'm open to
other ideas as well. I don't want to use CRON since the volumes of these
emails would be pretty high, and I'd rather reuse an already tested
solution for managing a task queue.