Exchange 2013 SP1 on Server 2012 R2 both fully patched. Exchange 2013 is a single server will all roles installed. There is also an Exchange 2007 (fully pathed) as we are in the process of migrating the users.

Setup legay.company.com points to Exchange 2007 and mail.company.com point to Exchange 2013

Security on Exchange 2013 set to NTLM for External and Internal. 

Mobile access works for user on Exchange 2013 and Exchange 2007

Client with Mailbox's on Exchange 2013 using Outlook 2010 - 2013 internally and externally getting prompted for username and password.

Clients with Mailbox's on Exchange 2007 ok.

Checked IIS, autodiscover, EWS and Kernal mode is set. 

Nothing showing in the Event Logs.

Hi,

I had experienced such an issue earlier.

once the Authentication settings have been changed did you try running IISRESET ??

coz in our case the changes didn't take effect immediately and it works after a IISRESET, also make sure to check the status in command prompt, IIS should stop and restart.

 An Auto discover test may also help  (hold down CTRL, right click on icon in system tray)

Try and let me know if this works

Thanks & Regards

John Chris

• Proposed as answer by SpaceDirt 20 hours 12 minutes ago
• Unproposed as answer by Skynite 20 hours 11 minutes ago

Yes I ran iisrest after making changes.

Autodiscover tests all complete with out any errors. E-Mail Autoconfiguration also works correctly. Outlook Connection status states protocol is RPC/HTTP and Auth is NTLM.

Hi,

I had experienced such an issue earlier.

once the Authentication settings have been changed did you try running IISRESET ??

coz in our case the changes didn't take effect immediately and it works after a IISRESET, also make sure to check the status in command prompt, IIS should stop and restart.

 An Auto discover test may also help  (hold down CTRL, right click on icon in system tray)

Try and let me know if this works

Thanks & Regards

John Chris

• Proposed as answer by SpaceDirt Monday, November 10, 2014 3:42 PM
• Unproposed as answer by Skynite Monday, November 10, 2014 3:43 PM

Hi,

I had experienced such an issue earlier.

once the Authentication settings have been changed did you try running IISRESET ??

coz in our case the changes didn't take effect immediately and it works after a IISRESET, also make sure to check the status in command prompt, IIS should stop and restart.

 An Auto discover test may also help  (hold down CTRL, right click on icon in system tray)

Try and let me know if this works

Thanks & Regards

John Chris

• Proposed as answer by SpaceDirt Monday, November 10, 2014 3:42 PM
• Unproposed as answer by Skynite Monday, November 10, 2014 3:43 PM

Hi,

I had experienced such an issue earlier.

once the Authentication settings have been changed did you try running IISRESET ??

coz in our case the changes didn't take effect immediately and it works after a IISRESET, also make sure to check the status in command prompt, IIS should stop and restart.

 An Auto discover test may also help  (hold down CTRL, right click on icon in system tray)

Try and let me know if this works

Thanks & Regards

John Chris

• Proposed as answer by SpaceDirt Monday, November 10, 2014 3:42 PM
• Unproposed as answer by Skynite Monday, November 10, 2014 3:43 PM

Hi,

alright, so this has to do with the authentication and maybe also with the Outlook client version.

I'll share a Link which I followed to resolve this... Hope it works for you.

//clintboessen.blogspot.in/2014/09/outlook-2010-and-exchange-2013-users.html

Let me know if that worked

Thanks & Regards

John Chris

please note: I've modified the LINK as my TechNet account still needs verification  

• Proposed as answer by SpaceDirt 4 hours 44 minutes ago
• Unproposed as answer by Skynite 2 hours 18 minutes ago

Thanks for the link, however I have the internal and external both already set as NTLM. Checked all the configuration and it appears to be correct. The only thing I would say is that I have the internal and external names set as the same.

Hi Skynite,

I have met this issue before, I recommend you try the following method and check the result:

In this situation, you must set LmCompatibilityLevel on the client to a value of 2. To do this, follow these steps.

• Click Start, click Run, type regedit in the Open box, and then press ENTER.<u5:p></u5:p>
• Locate and then click the following registry subkey: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\
• In the pane on the right side, double-click lmcompatibilitylevel.<u5:p></u5:p>
• In the Value data box, type a value of 2 and then click OK.<u5:p></u5:p>
• Exit Registry Editor.<u5:p></u5:p>
• Restart your computer.<u5:p></u5:p>

More details about this Key, please refer to the following link:

http://technet.microsoft.com/en-us/library/cc960646.aspx 

Best regards,

Hi,

But did you try setting up the external connection on BASIC authentication & NTLM for internal.

thanks

spacedirt

Hi,

also check if your Certificates are correctly assigned.

Thanks

John chris

Hi,

alright, so this has to do with the authentication and maybe also with the Outlook client version.

I'll share a Link which I followed to resolve this... Hope it works for you.

//clintboessen.blogspot.in/2014/09/outlook-2010-and-exchange-2013-users.html

Let me know if that worked

Thanks & Regards

John Chris

please note: I've modified the LINK as my TechNet account still needs verification  

• Proposed as answer by SpaceDirt Tuesday, November 11, 2014 7:10 AM
• Unproposed as answer by Skynite Tuesday, November 11, 2014 9:36 AM

Hi,

alright, so this has to do with the authentication and maybe also with the Outlook client version.

I'll share a Link which I followed to resolve this... Hope it works for you.

//clintboessen.blogspot.in/2014/09/outlook-2010-and-exchange-2013-users.html

Let me know if that worked

Thanks & Regards

John Chris

please note: I've modified the LINK as my TechNet account still needs verification  

• Proposed as answer by SpaceDirt Tuesday, November 11, 2014 7:10 AM
• Unproposed as answer by Skynite Tuesday, November 11, 2014 9:36 AM

Hi,

alright, so this has to do with the authentication and maybe also with the Outlook client version.

I'll share a Link which I followed to resolve this... Hope it works for you.

//clintboessen.blogspot.in/2014/09/outlook-2010-and-exchange-2013-users.html

Let me know if that worked

Thanks & Regards

John Chris

please note: I've modified the LINK as my TechNet account still needs verification  

• Proposed as answer by SpaceDirt Tuesday, November 11, 2014 7:10 AM
• Unproposed as answer by Skynite Tuesday, November 11, 2014 9:36 AM

I have a number of different clients this is happening to so I will test this but I think the issue is more server side.

Yes it was set like this but I changed it to both NTLM to see if it would resolve the issue.

Yes I have a wildcard cert and it has been added correctly and assigned to the services.

Hi,

External connection requires BASIC authentication, set it on outlook anywhere, do iisreset and restart information store service.

Thanks.

I have put External connection back to BASIC but still get the error.

I have ran Outlook.exe /rcpdiag and noticed that the password prompt box appears when it is attempting to connect to the Exchange 2007 server. The Exchange 2007 server still holds the public folders and a few users mailbox's as we have not migrated them all over yet.

The only thing that has been updated on the Exchange 2007 is that the certificate was updated as it was due to expire.

Hi Skynite,

Is there any helps after changing the value of LmCompatibilityLevel parameter ?

In addition, If you create a new mailbox on exchange 2013, and use outlook to connect this new mailbox, is there the same issue?

Best regards,

Hi,

On the problematic clients ,Make sure the internet explorer proxy exceptions contains autodiscover name and outlook anywhere names.

IMaking the change did not resolve the issue and also the same thinks happened with a new mailbox I created on 2013.

We do not use a proxy server but thanks for your input. I have raised a case win Microsoft and will let you know what they do to resolve the issue.

Hi Skynite,

Did you get the solution ?

If you got the solution, please post here and this will be beneficial to other community members as well. 

Thanks for your understanding!

Best regards,