This update isn't available since Cumulative Update 8 for Exchange Server 2013 (3030080) was released on March 17, 2015. You can install the latest Exchange Server 2013 update to get the improvements and fix the issues that are described in this article.
Cumulative Update 6 for Microsoft Exchange Server 2013 was released on August 26, 2014. This cumulative update resolves a list of issues.
Issues that the cumulative update resolves
This update resolves the issues that are described in the following Microsoft Knowledge Base (KB) articles:
2988229 Hybrid Configuration wizard error "Subtask CheckPrereqs execution failed" for Exchange Server 2013
2986779 EMS takes a long time to execute the first command in an Exchange Server 2013 Cumulative Update 5 environment
2983512 RPC Client Access service crashes on an on-premises Mailbox server in an Exchange Server 2013 hybrid environment
2983426 AutodiscoverSelfTestProbe fails when external URL is not set for EWS virtual directory in Exchange Server 2013
2983423 AutodiscoverSelfTestProbe fails when external URL is not set for ECP virtual directory in Exchange Server 2013
2983422 The ServerWideOffline component is set to Inactive after Exchange Server 2013 prerequisite check fails
2983207 "532 5.3.2" NDR when you send an email message to a hidden mailbox in an Exchange Server 2013 environment
2983066 Removed Default or Anonymous permission for Outlook folders cannot be restored in an Exchange Server 2013 environment
2982769 "Topology service cannot find the OWA service" when you perform an eDiscovery search in Exchange Server 2013
2982763 Mail-enabled public folder accepts email messages from unauthorized users in an Exchange Server 2013 environment
2982762 OAB generation arbitration mailbox can be removed or disabled in an Exchange Server 2013 environment
2982760 The Enter key submits duplicate sign-in forms to Outlook Web App in an Exchange Server 2013 environment
2982759 You cannot access the archive mailbox of a delegated user after enabling MAPI over HTTP
2982017 Incorrect voice mail message duration in an Exchange Server 2013 environment
2981835 You cannot add attachments, delete or move many email messages in bulk in Outlook Web App
2981466 MAPI/CDO client cannot connect to Exchange Server 2013
2977279 You cannot disable journaling for protected voice mail in an Exchange Server 2013 environment
2975599 Exchange Server 2010 public folder replication fails in an Exchange Server 2013 environment
2975003 Calendar item body disappears in Outlook online mode in an Exchange Server 2013 environment
2974339 OAB generation fails if FIPS is used in an Exchange Server 2013 environment
2971270 Blank page after you sign in to Exchange Server 2013 EAC (formerly ECP)
2970040 Folder Assistant rule does not work correctly in an Exchange Server 2013 environment
2965689 EAS device cannot sync free/busy status if an item is created by EWS in an Exchange Server 2013 environment
2963590 Message routing latency if IPv6 is enabled in Exchange Server 2013
2961715 "Something went wrong" error in Outlook Web App may show an incorrect date
2958434 Users cannot access mailboxes in OWA or EAS when mailbox database is removed
2993556 Sender's DKIM signature is broken in an Exchange Server 2013 environment
This update also includes new daylight saving time (DST) updates for Exchange Server 2013. For more information about DST, go to the following Microsoft website:
The setup process for Exchange Server 2013 will identify any missing prerequisites.
You have to restart the computer after you apply this cumulative update package.
You do not have to make any changes to the registry after you apply this cumulative update package.
After you install this cumulative update package, you cannot uninstall the cumulative update package to revert to an earlier version of Exchange Server 2013. If you uninstall this cumulative update package, Exchange Server 2013 is removed from the server.