Embodiments of the invention provide a scheduling process and apparatus which may include constraints which determine the amount of messaging events available in a particular category (e.g. sports, music, food content) in a particular time period, for example on a particular day (or perhaps even within smaller time periods, such as afternoon/morning slots or even hourly slots.) The amount allocated per category may vary according to the time period--so that, for example, Monday may be "Music Day", during which the content will be predominantly music-related. By having a variation period-by-period, e.g. day-by-day (or according to other slots) over a weekly (or other) period then the recipient becomes more familiar with, and involved in, receiving the message content. Since the recipient gets to understand the periodic formatting, they will come to expect a particular type of message content at a particular time, or at least during a particular period or timing characteristic.