Ever since migrating from Exchange 2007 to 2013 (migration done by an outside contractor) we have had issues with password popups on client machines.  All are Outlook 2010 on Windows 7 Pro joined to a domain.  For some people a rebuild of their Outlook profile fixed it, for others it was shared mailbox permissions being incorrectly applied, and for some people - nothing has seemed to fix it.  My Exchange experience is limited after 2007 - and I haven't found a 'smoking gun' yet.  Any ideas where to start troubleshooting?

It may help you

Go to file in outlook 2010 -> Click Account settings -> click account settings again ->  In Email TAB -Click change

Click More settings -> Click Security TAB -> Disable Always Prompt for logon credentials.

restart outlook.

Try to make outlook client as online mode.

hope this info help

Could you run the Outlook analyzer located in www.exrca.com?

This can tell us if there are configuration issues that can cause problems with the Outlook client.

Is not uncommon your issue, but there are a lot of causes for this. Sometimes the methods for internal and external OA are differents (one using basic and the other NTLM) and that lead a popup when the user change the network. Other times is the OAB web site messing around.

With the Outlook test tool you can check the global configuration and see if there is something wrong.

Hi thesupremeg33k,

Thank you for your question.

There are many reason which lead to type password randomly, we could refer to the following steps to troubleshoot:

1. Make sure there are no network issue in your organization;

We could consult network administrator to make sure there are no network issue in your organization, for example network loop

  2. Doing the Test Email AutoConfiguration to if there are any errors;

      Right click outlook icon and click Test Email AutoConfiguration>just choose Use AutoDiscover and click test

  3 .The Maximum Allowed Service Sessions Per User

     We could modify the value by the following link:

     https://technet.microsoft.com/en-us/library/ff477612(v=exchg.141).aspx

If there are any event ids on Exchange 2013, please send those event id to us for troubleshooting by ibsexc@microsoft.com.

We could refer to the following links:

https://social.technet.microsoft.com/Forums/en-US/950d1fb3-c106-4599-af0b-6a705da2fd51/outlook-2010-prompt-for-credential-when-connecting-to-exchange-2013-mailbox?forum=exchangesvrclients

https://social.technet.microsoft.com/Forums/en-US/97787724-2050-4a68-a3f8-f878bdee0d06/2007-to-2013-migration-issue-outlook-prompting-for-credentials?forum=exchangesvrdeploy

If there are any questions regarding this issue, please be free to let me know. 

Best Regard,

Jim