Better Late Than Never – Exchange 2013 CU1 Out Next Week!

Exchange 2013 CU1 Out Next Week!Exchange admins have been waiting with bated breath for the release of Exchange 2013 CU1, the version that will finally let us play with a mixed Exchange 2010/2013 environment. We might even get to throw a little 2007 in there! CU1 was supposed to be released during Q1 2013, which in case you hadn’t noticed, ends this Sunday. While it looks like Microsoft won’t quite make it in Q1, cut the guys a break-a two day delay is in our best interests!

In a posting on the Microsoft Exchange Team blog, Microsoft’s Ross Smith IV announced that, while the release of CU1 would not be during Q1, it would be released two days later, on April 2. While it is possible that the date might slip again, I expect that it won’t. Smith goes into some detail on the posting about why the need for a couple of more days.

Microsoft has been testing CU1 for probably months, in both lab environments and production. That production has included Microsoft’s own corporate email systems, and customers enrolled in the Technology Adoption Program, or TAP. During the last pass of testing coexistence with Exchange 2010, an issue was identified. While Microsoft could have proceeded with releasing CU1 and then requiring customers to make a change on their Exchange 2010 CAS servers to work around this issue, the decision was instead made to implement a change in code on CU1 so that customers would not have to make any more changes to their Exchange 2010 system than absolutely necessary.

As an Exchange 2010 admin, I appreciate this decision. The less I have to do in production to start introducing Exchange 2013, the better, and making a change on existing production systems would require more change controls, more testing, and generally, a lot more effort than simply tweaking a setting or editing a registry key might imply. By making the fix in CU1, it’s that much less we’ll have to worry about in production, and that is good for everyone. A two day slip is really a non-event to me, since whether they released it on Friday the 29th or Tuesday the 2nd, it will be well into next week before most of my customers could even consider starting their deployments.

For those of you who are anxious to deploy, remember the following.

  • New Exchange org-you can start with Exchange 2013 today.
  • Existing Exchange 2010 org-you need to apply Exchange 2010 SP3 to all your Exchange 2010 servers and then you can start to build your first Exchange 2013 systems when CU1 is released next week.
  • Existing Exchange 2007 org-you need to apply Exchange 2007 SP3 RU10 to all your Exchange 2007 servers and then you can start to build your first Exchange 2013 systems when CU1 is released next week.

We’ll keep a close eye on the availability of Exchange 2013 CU1, and will post any updates as soon as we can, or the link to download once the bits are available.

Written by Casper Manes

I currently work as a Senior Messaging Consultant for one of the premier consulting firms in the world, I cut my teeth on Exchange 5.0, and have worked with every version of Microsoft’s awesome email package since then, as well as MHS, Sendmail, and MailEnable systems. I've written dozens of articles on behalf of my past employers, their partners, and others, and I finally decided to embrace blogging and social media, so please follow me on Twitter @caspermanes if you enjoy my posts.


  1. Ivy Anthony · March 30, 2013

    Obviously, a lot of Microsoft users are waiting for this. I’m not really familiar with Exchange 2013, but I do know that it helps email users do a lot more than send, well, emails. I know that certain features enhance the email experience. I also know that CU1, or Cumulative Update 1, is something that will help Exchange function better. CU1 allows Exchange 2013 and 2010 to co-exist. It will make tasks easier for anybody. In my opinion, Microsoft has produced a “big bang” here as Exchange 2013 CU1 is definitely something that elevates the email experience to a higher level.

  2. Stephen Rowson · April 3, 2013

    Well, Microsoft has just released the much-awaited Exchange Server 2013 update about 19 hours ago. You can download it here:

    Nothing much about the update but I was really impressed on how they fixed some mailflow and mailbox issues. For instance, the update is now able to give solutions to problems related to NTLM authentication, TransportAgent cmdlets, mailbox size increase, Address Book Policies and Offline Address Book. You can get more details about the CU1 update here:

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