This is not very common these days but still some organizations are other three months behind or six months behind the Exchange 2013 Cumulative Updates. or you may have setup a new Exchange 2013 you may want to bring it up to the updated CU.
So if you are even no onto the CU11 , below are the some important (depending on the scenario) updates it covers, not all are very important but some of them are very critical .
Here is the list of important updates in my opinion I’d consider upgrading to CU11.
- KB 3120594 Appointment on the Outlook calendar isn’t updated to a meeting when attendees are added – this has high impact on the end-user.
- KB 3108011 Error message occurs in Outlook after you change a single instance of a recurring meeting by using an iOS device – another end-user impacting issue. almost every organization uses mobile device managed or non-managed.
- KB 3107337 Mailbox migration from Exchange Server 2007 to Exchange Server 2013 is very slow – only if you are migrating from Exchange 2007 to Exchange 2013
- KB 3105760 Exchange Server 2016 mailbox server can be added to an Exchange Server 2013 DAG – this by design and by design you can’t have two different version of Exchange mailbox servers in a DAG, this is a version conflict.
- KB 3105690 Outlook clients that use MAPI over HTTP to connect to Microsoft Exchange Server 2013 mailboxes are intermittently disconnected – this is highly visible to the end-user and must be fixed.
- KB 3105625 ActiveSync device downloads emails while it’s in quarantine in an Exchange Server 2013 environment
- KB 3093866 The number of search results can’t be more than 250 when you search email messages in Exchange Server 2013
- KB 3088487 IOPS Write increase causes email delivery delays in an Exchange Server 2013 environment
- KB 3048372 Exchange Calendar items are shifted incorrectly when some Windows DST updates are applied
- KB 2968265 OWA cannot be accessed after you upgrade Exchange Server 2013
To get the full list of al the update here is the TechNet url
https://support.microsoft.com/en-us/kb/3099522
