Before I finish off my series about iSCSI and Exchange 2007 SCR I would like to add a post about some things that has been driving me crazy in one of my production environments (which is in Interop Mode).

Essentially the problem that I was having is very similar to a number of well documented problems on the Internet which relate to the Exchange 2007 Out of Office service.

The environment is which I was having problems was made up of a pair of clustered Windows 2008 Exchange CCR server – two Hub Transports and two Client Access servers – additionally as this was a migration environment I also had a pair of Windows 2003 Exchange 2003 Active / Passive Clusters with a pair of Front End Servers.

The symptoms of the problem that I was getting were:

• People whom had mailboxes on the CCR based clusters could set their OOF via Outlook 2007 and OWA 2007 – but the OOF message WOULD NOT send (either internally or externally).
• People whom had mailboxes on the CCR based cluster could set their OOF via Outlook 2003 and with WOULD work both internally and externally
• If those people whom had set their OOF via Outlook 2003 then tried to change their OOF via OWA 2007 – the OOF reply will still remain as the version the set in Outlook 2003
• OOF Messages set in OWA 2007 or Outlook 2007 would not sync with Outlook 2003

After much messing around with this issue I decided to turn to Google, and found that there are a large amount of articles on the web which describe (or are at least very similar to the problem that I was having) logged by many people – below are some examples that I came across which initially gave me hope:

http://blog.flaphead.dns2go.com/archive/2008/07/08/blackberry-exchange-2007-ooo-issue.aspx – A good article by Paul Flaherty, however mainly centred around the OOF functionality not working in conjunction with Blackberry Enterprise Server – therefore not strictly relevant to me – but an indicator none the less that something was amiss in the OOF functionality.

http://www.msexchange.org/articles_tutorials/exchange-server-2007/tools/troubleshooting-out-of-office.html – an Excellent article by Neil Hobson which explains the differences between the OOF settings in Outlook 2003 (and Exchange 2003) and Exchange 2007 (and Outlook / OWA 2007) and how you can troubleshoot the problems. Neil’s article was informative but seemed to stem around the concept that individual mailboxes did not work – whereas with me it was all mailboxes which were on an Exchange 2007 Server.

To be on the safe side, I tried all of the suggestions that Neil made to now avail – I still had the same problems listed above.

http://msexchangeteam.com/archive/2007/04/04/437544.aspx – This article again was very informative (from the Exchange team) but generally speaking it takes you through the caveats of using different versions of Outlook with the new features of the OOF functionality in Exchange 2007 – nothing in here gave my a clue to how I could solve my problems.

Over the next few weeks I went between the Internet and many, many hundreds of forum articles about this subject and indeed a number of test runs in my lab (all of which worked fine in the lab – by in my production scenario would not work at all).

I was now getting desperate – and indeed with a project check point looming and still no progress on this rather irritating problem I have to admit I was considering a rebuild (which is always my last resort). So to ensure that I did not jump to any rash conclusions I decided that I was going to “take my mind” off things and do some documentation this would free my mind from the problems and pending review – and perhaps allow me to come back to the problem with a fresh view.

So I switched over to my documentation – which ironically was collating information about the services which run on each Exchange server and how they interact.

There I was working away through the services until I hit the “MSExchangeMailboxAssistants” service – which as per the Microsoft Exchange online help file describes as:

Provides functionality for Calendar Attendant, Resource Booking Attendant, Out of Office Assistant, and Managed Folder Mailbox Assistant. This service is dependent upon the Microsoft Exchange Active Directory Topology service.

This I suppose is one of those “Eureka” or “Doh” moments – I quickly logged onto the active node of my CCR Mailbox Clusters and discovered that the service was set to “Automatic” but was not running. I checked all of the other nodes in the clusters and found that the service was in the same state. I quickly started the service and did some testing – guess what – full OOF functionality was restored – yee haa it works.

This of course now presented the question as to why the service was not started – so I did some testing. It would seem that the MSExchangeMailboxAssistants does not always come back online when a CCR node fails over (and as I am in an Interop scenario had been testing the failover properties throughout the project) – so something to bear in mind is that if you make use of either SCC or CCR clustering and you have a failover you should check to see if all your services have restarted correctly.

Indeed if you are having problems with the OOF functionality in Exchange 2007 – and it does not appear to be the MSExchangeMailboxAssistants service – have a look at the articles that I have suggested above which have been written by others – they also might yield a solution to your problems.