The third phase of the upgrade involves Exchange. As with most small companies, Tailspin Toys uses a single Exchange server as well as Public Folders. They had been using the IMF along with the different filtering options available with Exchange 2003 along with other 3rd party anti-virus and anti-spam tools.
The Exchange Forestprep and Domainprep phases finished with no issues. The installation of Exchange Server 2010 SP1 also completed with no issues. We setup a test user and mailbox on the new Exchange 2010 server to test email flow. There were no issues with email flowing from the Internet and the old Exchange 2003 server to the 2010 server. However, everything outbound from the 2010 server was stuck in the queue. Even after turning on event reporting to the highest levels, the only useful information I got was that the connection from the 2010 server was being denied by the 2003 server. Doing some Bing (and even google) searches only revealed one item that seemed to apply – entering an IP exception for the 2010 server to connect. This did not help and so I focused on getting the other components of 2010 configured – Autodiscover, Offline Address Book, etc. Since Public Folder replication required two way communications between the two Exchange servers, I had to put that one on hold as well until I figured out the issue.
It took me a little digging on what would block SMTP connections to an Exchange 2003 server before it hit me that the IMF and Filtering settings could possibly be the culprit. As a quick test, I disabled all Filtering options on the 2003 server and voila, the queue on the 2010 server cleared up and we were able to get full email flow!!! We then moved the smallest mailbox from 2003 to 2010 as a test. This worked successfully and once again we successfully tested all email flow scenarios using this active mailbox. We moved one more mailbox and reran our test scenarios successfully before we initiated a massive move of all the mailboxes. Unfortunately, we had 3 mailboxes that failed to move with an error stating the mailbox could not be opened. Since the moves took some time, I didn’t have time to trouble shoot right away so they ended up running with most mailboxes on the 2010 server but three on the old 2003 server. We also moved all the Public Folders over to the 2010 server on that first weekend.
I did some quick searches to see if I could figure out the issue associated with the three mailboxes that had permissions issues, but didn’t find anything that was helpful. Instead, I decided to look at the permissions on the user objects that were affected and compared them to the ones that worked. For some reason, the security was out of whack on these three accounts and I corrected them to match the ones that worked correctly. After making those changes, the final three mailboxes moved successfully.
At this point, the new DC / GC was fully operational, the File & Print servers were handling all the core workloads and the new application servers were in full swing. The Exchange 2010 server was handling all email responsibilities and Tailspin Toys was fully operational on the new infrastructure. The last phase left was removal of all the old servers. I will cover that in the next post.