iOS6 and ActiveSync bug fixed in Zarafa/Z-Push

Yesterday Zarafa published a blog post in which they announced their fix for the iOS6 ActiveSync appointment issue.

For those who don’t know, Zarafa is an open source Exchange clone (a bit like Zimbra) and uses the open source “plug-in” Z-Push for its server side ActiveSync implementation.

Although the work seems solid and commendable, I do have some issues with the post (No, I’m not trying to be mean). Especially when they describe their fix for Exchange (which is not the main focus of the post BTW):

How to fix it in Exchange

The real fix is that Apple changes the organizer logic back to what it was, or even better, uses the MeetingStatus field in the WBXML response to find out if it is an organizer. I don’t know why this wasn’t done in the first place.

If you do any of the following, the chance of it happening will be lower, but not zero:

– Make sure you send meeting requests only to the delegate, not to both the attendee and the delegate. (this is an option in your delegation options in Outlook)

– Turn off the inbox assistant (which has various names in various Exchange versions), which automatically processes incoming meeting requests

My main issue is with the term fix. If it’s an issue, only Microsoft can fix it with an hotfix, rollup update or service pack etc.. What they describe here is a workaround. The issue is still there, but you have changed your own behavior in order to circumvent the issue. That is NOT a fix.

As for the suggestions the first one is a change in user behavior, which is probably difficult to achieve. The setting can possibly be changed via GPO (I haven’t checked).

The second suggestion has more impact (disabling the Calendar attendant for each mailbox), especially if you have room mailboxes. Personally I would consider using Allow/Block/Quarantine (ABQ) to filter iOS devices, this way you keep functionality and users can still manage appointments via Outlook and OWA.

It depends on your situation which limitations you can live with, but as Exchange MVP Paul Robichaux wrote in a blog post about this issue and the Zarafa/Z-Push solution, it’s probably also an issue that you could live with.

Having said this all, do check out their blog post as it is still an interesting read.

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