The Message Scheduler continually checks for new messages being scheduled by Mailing Tank clients. When it detects that a new message has been scheduled, the scheduler queries the database for what member records and demographic data will be needed and then passes that information on to the personalisation engine. The scheduler system has a built-in efficiency algorithm that ensures that no message waits in the queue for too long.

The message scheduler also acts as a monitoring system for scheduled messages. Once a mailing has begun delivery the scheduler checks for end-user pause requests, as well as monitoring the delivery rate of each message.