sendMessageDenyNotification property
Allows a member to be notified if the member's message to the group is denied by the group owner.
Possible values are:
- 
true: When a message is rejected, send the deny message notification to the message author. The defaultMessageDenyNotificationText property is dependent on the sendMessageDenyNotification property being true. 
- 
false: When a message is rejected, no notification is sent. 
Implementation
core.String? sendMessageDenyNotification;