I have an ongoing Exchange 2013 problem with some users not being able to add/edit Calendar entries into the Calendars of other users. I'm hoping for a clue as to why this may be happening.
We have an open calendar policy in the company in which all users should be able to see/edit any entry in another calendar and to employ this policy, a previous Exchange admin has run a PS script which changed the Default user permission to {PublishingEditor}.
See below for an excerpt of a random user's calendar permissions.
FolderName User AccessRights
---------- ---- ------------
Calendar Default {PublishingEditor}
Calendar Anonymous {None}
Calendar Rob B {PublishingEditor}
Calendar Global Leave Appr... {PublishingEditor}
Calendar Managers {PublishingEditor}
Calendar Calendar Administ... {Editor}
I have managers trying to enter an appointment into this person's calendar only to have outlook tell them that access is denied. It seems to happen randomly and to different people (it will work some days and not others). Our users use a range of clients from Outlook 2007, 2010 to 2013.
At first I thought it was due to nested distribution groups within security groups and an inheritance issue of some sort but reviewing the permissions, there should technically not be any issues considering the Default permissions across all calendars are {PublishingEditor}.
I guess the only potential cause I can see with a denial of access seems to be the Anonymous user; maybe there is some background issue where users are not being authenticated? There's nothing else anywhere that would serve up a deny for access. What is everybody's thoughts on the matter?
UPDATE:
I've updated Exchange to CU5 in case there were any hotfixes which addressed this issue. There were some indexing errors which I have no reindexed and confirmed they are healthy. I've also reconfigured most of the AccessRights on all mailbox calendars to be the following:
Default {Editor}
Anonymous {AvailabilityOnly}
Calendar Administrators {Editor}
One particular user is a member of Calendar Administrators but is still experiencing issues - he cannot view several calendars now.
It turns out the users being affected were accessing up to 30 calendars in any one session. For some reason, the outlook clients were saturating all available connections to the server and then once reaching the limit, would produce the symptoms identified.
The issue was resolved with modifying the throttling policy on the exchange server.
This issue can occur when using Cached Exchange Mode in the Outlook. Try the following Outlook settings (These instructions are for Outlook 2010):