![Exchange Online Hybrid - Autodiscover works for Outlook 2016 clients, but fails for Outlook 2013 - Server Fault Exchange Online Hybrid - Autodiscover works for Outlook 2016 clients, but fails for Outlook 2013 - Server Fault](https://i.stack.imgur.com/V0ItD.png)
Exchange Online Hybrid - Autodiscover works for Outlook 2016 clients, but fails for Outlook 2013 - Server Fault
![Exchange 2013/2016 – Outlook cannot connect to Exchange server with MAPI over HTTP only internal. | Exchange-Fix Exchange 2013/2016 – Outlook cannot connect to Exchange server with MAPI over HTTP only internal. | Exchange-Fix](https://anotherexchangeblog.files.wordpress.com/2017/10/capture1-redone.jpg)
Exchange 2013/2016 – Outlook cannot connect to Exchange server with MAPI over HTTP only internal. | Exchange-Fix
How to fix Outlook to The connection to Microsoft exchange is unavailable. Outlook must be online or connected to complete this action- Internal connect
![Outlook connection issues with Exchange mailboxes because of the RPC encryption requirement - Exchange | Microsoft Docs Outlook connection issues with Exchange mailboxes because of the RPC encryption requirement - Exchange | Microsoft Docs](https://docs.microsoft.com/en-us/exchange/troubleshoot/exchangeserver/client-connectivity/media/outlook-connection-issue-caused-by-rpc-encryption-requirement/exchange-encryption.png)