For example if you attempt to delete a meeting, the Send Cancellation form automatically appears.You cannot save this change without clicking the Send Cancellation button to send the cancelation email.Outlook was designed to send updates when you change the location or time of the meetings because the attendees need to know when and where the meeting is.You also can't avoid sending an update when you add a attendee, for the very same reason.For more information see: Exchange Outlook Calendaring Problems.Exchange itself is usually not the root of the problem, the mail clients (Active Sync, i OS devices, Blackberries, i Cal) and their connectivity protocol tend to be the culprits. For instance, if someone accepts a meeting at 9am on an i Phone and a delegate declines it at am on a PC, but the i Phone is out of signal range and doesn't sync the meeting until say am., what happens to the meeting?The easiest way to verify this is the problem is to log in to your Outlook Web Mail, if you are using Office 365 you can log in at https://portal.using your username and password.
In a few words, in Outlook 20 you can no longer make critical changes on a meeting without sending an update.
An Informational update is an update that does not require any action from the attendee.
As the name states, it was designed to simply inform the attendee of specific changes that have occurred on the meeting.
If you are making use of shared calendars in Outlook 2016 you may find that not all appointments are showing in the calendar or are disappearing.
Typically this happens when running Outlook 2016 in cached mode with exchange or Office 365.