Update Rollup 19 for Exchange 2010 Service Pack 3 is now available for direct download. It contains 1 documented new fix and all previously released fixes and security updates for Exchange 2010 SP3. Note that mainstream support for Exchange 2010 has already ended.
- KB4054456 EWS connections proxied from Exchange Server 2016 to 2010 can access all the Exchange 2010 mailboxes
View: Description of Update Rollup 19 for Exchange Server 2010
Download: Update Rollup 19 For Exchange 2010 SP3 (KB4035162)