Just a quick heads-up on support for Exchange 2007. Mainstream support for Exchange 2007 ended on April 10, 2012 and Extended Support will end on April 11, 2017. Rollup updates might be made available for another 2 years but you at this moment you should be planning to upgrade your platform.
I am always amazed by the amount of customers running Exchange 2007 or Exchange 2010 and NOT using Autodiscover. Their response is always “we don’t need it” and “we configure the Outlook profile manually”. In Exchange 2007 and Exchange 2010 you can get away with this (you cannot with Exchange 2013 and Autodiscover is mandatory) but when you want to implement a hybrid scenario with Exchange online you really need Autodiscover since Exchange Online uses Autodiscover to find relevant information regarding your on-premises Exchange environment.
Recently a customer with Exchange 2010 wanted to build a hybrid environment with Exchange Online, and one of my first findings was the lack of Autodiscover. So, after configuring their Exchange environment and creating the necessary DNS records Autodiscover was working properly as shown in the following picture:
I am working with a customer that’s running Exchange 2010 on-premises and want to move to Office 365 in a hybrid scenario. The hybrid servers are running Exchange 2010. After implementing a hybrid scenario everything was working fine, but after some time I received calls that free/busy wasn’t working correctly anymore.
When a user with a Mailbox in Exchange online and he wants to schedule a meeting with a Mailbox in Exchange 2010 on-premsises all goes well and the user can see all free/busy information from all users.
When a user with an on-premises Mailbox (on Exchange 2010) wants to schedule a meeting with a Mailbox in Office 365 free/busy information from a Mailbox that’s not Domain joined he cannot check the availability information from Mailbox in Exchange Online as shown in the following screenshot:
Recently I had to reinstall my entire infrastructure, and one of the servers was the Office Web Apps server. Unfortunately the server was willing to do anything, the only thing I got was a white screen, or the ‘old’ WebReady Document view appeared. The discovery URL (https://webapps.exchangelabs.nl/hosting/discovery) was working fine, so at least something was working.
Another thing that was clearly visible was that processor utilization regularly peaked to 100%, sometimes staying at 100% for a longer period of time:
One of the first steps in troubleshooting your Exchange environment (or any Windows environment) is checking the Event Viewer. The Application log shows tons of entries, and step one is to filter out only the Error messages: