Edit: Update Rollup 18 is now available for Exchange 2010 SP3 see the post Exchange 2010 SP3 Update Rollup 18 installation tips.
On May 27th Microsoft released the Exchange 2010 SP3 Update Rollup 6. The Update Rollup 6 for Exchange Server 2010 SP3 contains the fixes for the security issue that is described in KB2936871.
The update can be downloaded from here.
I’ve installed this on my test SBS 2011 server, it took just 18 minutes from start to finish, and my test SBS server isn’t very powerful. So I wouldn’t expect this to take much longer than this in production.
As ever you may want to consider waiting a couple of days before deploying the update rollup in your production environment, as it has been two weeks since it’s release and I’ve not heard or any horror stories I think you should be alright.
While looking for others experience of installing the update rollup I’ve come across a few suggestions that might help speed the install up and a few best practice tips.
1. Reboot the server prior to installing the update rollup. If it has been up for a while a reboot will make sure it is in a know good state.
2. Run the update from an elevated command prompt.
3. In Internet Explorer, deselect “Check for Publisher’s certificate” and “Check for server certificate revocation”, from Internet Options, Advanced tab, Security options.
4. Disable antivirus software.
5. Have a full backup and a system state backup of the server.
6. Make sure the SBS console is closed if installing the update on SBS 2011.
While the update is installed it will automatically stop Exchange and IIS services, and restart them again once complete.
Once the update has finished, remember to undo the changes made in steps 3 and 4 above.