On March 29th we posted an announcement to the EHLO blog about removing Update Rollup 3 for Exchange Server 2007 SP3 due to an issue that could result in database corruption.
The Exchange Servicing team has fixed the reported issue with RU3 and is making available a new version of RU3 for our customers, version 08.03.159.002, (KB2530488). We strongly advise all customers install this newly released version of Microsoft Exchange Server 2007 SP3 Update Rollup 3 and to discard any prior version of RU3 (KB2492691) which you may have.
RU3 Installation Guidance:
It is not necessary for you to uninstall the existing RU3 within your environment. The new RU3 package can be installed over the top of the existing package installed on your servers.
You can simply install the new version of the RU3 package.
General RU Installation Guidance
We deeply regret the impact that these issues have had on our customers, and as always, we continue to identify ways to better serve your needs through our regular servicing releases.