When you are set as Out of Office, any discussion you are subscribed to in an event will send an Out of Office reply (either your saved personal reply or the 'default' reply) to the comment thread. This will only happen when a comment is added by another User, and will only automatically reply once per discussion per day. You will not receive any email notifications while you're set as Out of Office, but your notifications within the application will still remain active as usual, meaning that when you return back to the office, you can catch up on any important event activity you may have missed.
Have more questions? Submit a request