I have a user who issue a problem with the email sync between the client (Surface Pro 3, Win 8.1 Pro) Outlook 2013 and Our Exchange 2010 server.

When the user travels from home to work or so likely, the email works fine. Until the user is located at the company, the exchange mostly fails to sync mails to the outlook - even several reboots or restart of outlook solves the issue sometimes. 

We have tried to perform clean install on surface and clean install of Office 2013.

recently was yesterday it did disconnect at ~14.00 CEST (local time) until 16.00 CEST (local time) where the user made me aware of the problem.

During logfiles i seen tons of theese messages with 3 seconds delay

13:51:39 The connection to Microsoft Exchange has been restored.
13:51:38 The connection to Microsoft Exchange has been lost. The connection is restored when possible.

During this, the outlook was not synced with the recent emails, however it was connected to exchange server by LAN-connection. On the users mobile device, the emails received meanwhile was received!! 

Also, sometimes appointments in the calendar suddently disappears with no warning?

I can't simply figure out what cause this problem - I hope you maybe can guide me to solve this issue!!

Hi,

Basically the issue only occurs when you are not using Lan connection in the company, correct?

The problem may be related to the Outlook Anywhere settings, I suggest you check this first:

In Outlook 2013, File -> Account Settings -> Account Settings -> Double click on the account name -> More Settings -> Connection.

Have you selected "Connecto the Microsoft Exchange using HTTP"? I suspect if you don't use LAN in company, Outlook is connecting via RPC over HTTP. Please continue to click "Exchange Proxy Settings" button, select "On slow networks, connect using HTTP first, then connect using TCP/IP" to check the result.

Since I haven't known if you have tried these settings, you can try other settings in the dialog to check the result too.

Regards,

Melon Chen
TechNet Community Su