Recommendations to avoid IOS Calendar Corruption with Exchange Mailboxes

Scenario: An entry on an IOS calendar shows incorrect times for an appointment, has disappeared, or is missing information, although the calendar entries in OWA and Outlook is correct. Specifically a single occurrence of a repeat appointment/meeting has one of the symptoms from above.

Recommendations from support:

1. Microsoft recommends running the same version of Outlook on all the computers. Mailbox owners and any delegates need to be using the same version of Outlook with the latest updates on all the computers that are used for calendaring. If you are in a mixed environment of Mac, Windows and iOS devices, each platform needs to be using the same version and each device should have the latest updates. 

2. Only one person should process meeting requests. Other people, computers or devices that receive the meeting request should ignore them, they should not delete or process them. Users should have a maximum of 2 delegates.

3. Manage your calendar exclusively from Outlook or OWA. Don't accept, decline, modify or invite others to appointments from your mobile device. You can create new appointments on your mobile device.

4. Verify that the device has the latest iOS version installed. (Please verify this before adding the Exchange account to the device. Sometimes, new devices are running an older version of iOS, so it is a good habit to confirm that all updates are applied before adding Exchange accounts)

5. To change an entire series of meetings, cancel the original meeting and create a new one. To change one instance, cancel just that meeting and create a new one to replace it. Always put an end date on a recurring meeting.

6. A "corrupt" meeting will remain that way until you delete it. If it is a recurring appointment, delete all occurrences and reschedule it.

7. When scheduling a recurring meeting, Microsoft recommends setting the end date no more than 6 months. If you need to schedule a meeting for a longer period, start a new recurring meeting.

8. Making multiple changes to recurring events can contribute to unexpected results.