Hi,

In our organisation are several clients with Oultook 2013 that have to disable IPV6 on there network adaptor. Otherwise they have from time to time connection issues, Outlook trying to connect.

Is this normal behaviour?

We have a hybrid environment with all mailboxes in the cloud.

Best regards,
Steven

Hi Steven,

This issue may occur if you use Outlook Anywhere externally in an Exchange Server 2007 and Exchange Server 2013 coexistence environment.

This issue occurs because the DSProxy component does not support connections that use the IPv6 protocol in the scenario that is described in the "Symptoms" section. Therefore, the DSProxy component cannot resolve Outlook clients.

To work around this issue, use one of the following methods.

Method 1

Install the Client Access role and the Mailbox role on different member servers.

Method 2

Disable IPv6 on only the Exchange Server 2007 member server that has the Client Access role and the Mailbox role installed. For more information about how to do this, click the following article number to view the article in the Microsoft Knowledge Base:

929852 How to disable IP version 6 or its specific components in Windows

For more information, please refer:

http://support.microsoft.com/kb/2794253

http://blogs.technet.com/b/rmilne/archive/2014/03/19/exchange-2007-2013-outlook-anywhere-coexistence.aspx

In addition, since this issue is more related to Exchange server, if above doesn't resolve the issue, I'd recommend you post a new question in the Exchange forum for further assistance:

https://social.technet.microsoft.com/Forums/office/en-US/home?category=exchangeserver

The reason why we recommend posting appropriately is you will get the most qualified pool of respondents, and other partners who read the forums regularly can either share their knowledge or learn from your interaction with us. Thank you for your understanding. 

Steve Fan

Forum Support