Edit: Update Rollup 18 is now available for Exchange 2010 SP3 see the post Exchange 2010 SP3 Update Rollup 18 installation tips.
Microsoft released the Exchange 2010 SP3 Update Rollup 16 on 13 December 2016.
I installed Update Rollup 16 on my test SBS 2011 server this evening and it took about 10 minutes from start to finish, so I wouldn’t expect it to take much longer than this in production.
Please test before installing into your production environment. Maybe even wait a few days or a week or two from the release date to make sure the QA is up to scratch on it.
For migrations to Exchange 2016, Exchange 2010 SP3 Update Rollup 11 is the minimum version that will be supported in a coexistance environment.
The update can be downloaded from here.
The official Exchange Team blog post can be found here.
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.
7. Backup any OWA customisations you have in place.
8. Stop any Backup Exec services if you have it running locally.
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.
The Microsoft Technet http://technet.microsoft.com/en-us/library/ff637981.aspx is a useful articles you may want to check out for further reading prior to installing the update rollup.
In larger multi-server envrionments apply Exchange 2010 Service Packs and Update Rollups in the following order (source: Technet) :
1. Client Access server
2. Hub Transport server
3. Mailbox server
4. Unified Messaging server