All emails sent from the Foundations CRM are processed through an email queue. The queue is then process through a task manager. The task must be scheduled in order to have emails consistently sent from your CRM. Email throttling (limits) maybe imposed based on your own preferences or the stipulations of your ISP.
Throttling limits can be set in your CRM Sechedule.
Setting up Email Queue task processing
Your task will run at the next scheduled start time.