One of the questions which is frequently asked on the forums after a new Exchange Server update is whether or not Enterprise Vault will work with it, and whether it will be supported. For the most part in the past, roll-ups or cumulative updates weren't specifically tested and called out individually. Customers could contact Support, and if an issue was found, it would be worked on and (hopefully) fixed.
Microsoft, in their wisdom, changed things a bit with Exchange 2013. The Cumulative Updates there are more like service packs than every before. Take a look at the table below for an example of what I mean:
Exchange 2010:
With Exchange 2010 come service packs, and then update rollups after that.. then another service pack, and more update rollups.
Exchange 2013:
With Exchange 2013, the service pack is just blended in with the cumulative updates.
So with Exchange 2013 the cumulative update revisions are important when it comes to Enterprise Vault, to the point that just the other day the following technote was published:
Enterprise Vault support for Microsoft Exchange 2013 CU6
If you plan to upgrade Exchange, it is well worth looking for these type of articles, and subscribing to them, so you will be notified of updates.
