Selecting this option provides the ability to cancel messages in the pending queue. What you right click on will determine who these messages go to. For example, if you right click on the Groups heading and select this option, this will cancel messages for all groups. If you right click on a specific group's name, this will only cancel messages for the selected group.
•Cancel all past due messages
Enabling this option will cancel past due messages. Past Due messages are Repeating Messages that should have been delivered but haven't, which can possibly interfere with the schedule of messages waiting to be sent.
•Cancel all pending messages
Enabling this option will cancel all messages in the pending queue for the selected object.
•Cancel all repeating messages
Enabling this option will cancel all repeating messages scheduled by the PageGate Client.
For example, if you have a message set to repeat every hour, enabling the "Cancel all repeating messages" option will stop that message from ever happening again where only enabling the "Cancel all past due message" option will only cancel any previous repeating messages that couldn't be delivered out but will not prevent future repeating messages from being sent.