[Professional and Corporate Editions Only]
AY Mail offer two different types of scheduling. Both methods require sending through AY Track.
If you want to send your message at a particular time in the future you can select File->Schedule from the main menu. AY Mail will compose messages and transfer them to AY Track. AY Track will not send the message right away, but will wait util the specified time.
The sending may take some time, especially if there are many recipients, and therefore the message is not guaranteed to be sent at the exact moment, but AY Track will not send it before the specified moment, and it'll start trying to send as soon as the moment comes.
Note that the message is composed at the time of scheduling, so any subscequent changes to the recipient list will not affect the sending.
If you want to send your message when it is convenient, such as during nights or low network traffic periods, you can configure AY Track weekly schedule to allow sending only at perticular times. To specify a sending schedule, select Settings->AY Track->Mail Sending from the main menu, then click on the Timing button. The AY Tack Timing Parameters dialog will appear to help you specify the schedule.
You can freely combine both scheduling methods.