Disabling MAPI over HTTP for Outlook on Enterprise Vault servers

MAPI over HTTP was introduced with Exchange server 2013 SP1 for Outlook 2010 SP1 (with updates KB2956191 and KB2965295) and Outlook 2013 SP1 or later. For more information on MAPI over HTTP, refer to https://technet.microsoft.com/en-us/library/dn635177(v=exchg.150).aspx.

Enterprise Vault does not support the use of MAPI over HTTP connections from Outlook 2013 SP1 on the Enterprise Vault server. For this reason, you must disable MAPI over HTTP connections by setting a registry value on each Enterprise Vault server as follows:

1. Log on to the Enterprise Vault server as the Vault Service account. If you run Exchange archiving tasks under a service account other than the Vault Service account, log on to this other account.
2. Create a registry DWORD value called MapiHttpDisabled under the following registry key:
   HKEY_CURRENT_USER\Software\Microsoft\Exchange
3. Assign MapiHttpDisabled a value of 1.
4. Restart Outlook on the Enterprise Vault server.

For more information, see the following article: http://blogs.technet.com/b/exchange/archive/2014/05/09/outlook-connectivity-with-mapi-over-http.aspx

Note that Outlook 2016 on Enterprise Vault server supports MAPI over HTTP connection in Enterprise Vault 12.2 or later.