NTLM authentication to Microsoft Outlook 2007

[Dharmesh Arora]

Hello Everyone,

I would like to know that is there any possibility by which i can set up Microsoft Outlook 2007 to use only NTLM authentication. Does any one have any idea about it that how can i do so? Please suggest me your views for the above issue. Any information or any kind of suggestion would be appreciated.

Thanks in advance.

[Milton.J]

By default, in the original release (RTM) version of Exchange 2007, the /rpc virtual directory was enabled for both Basic authentication and Integrated Windows authentication and could not be modified. Even if you were only using one authentication method, both authentication methods were always enabled for the /rpc virtual directory. Because using a single authentication method will help you reduce attack surface area, in Exchange 2007 SP1, you can now choose to use only one authentication method on the /rpc virtual directory. However, you can still also choose to allow both Basic and Integrated Windows authentication.

For new installations of Exchange 2007 SP1, by default, the authentication method on the /rpc virtual directory will be the same as the authentication method that you choose when you enable Outlook Anywhere by using the Enable Outlook Anywhere wizard. The default authentication method for Internet Information Services (IIS) can be modified by using the Set-OutlookAnywhere cmdlet to be either Integrated Windows authentication or Basic authentication or both. As an alternative to using the Enable Outlook Anywhere wizard, the Enable-OutlookAnywhere cmdlet can be used to configure Outlook Anywhere.

[Spyrus]

To change the authentication mechanism on the Outlook client to NTLM, follow these steps:

1. Start Outlook 2003/2007. On the Tools menu, click E-mail Accounts or Account Settings, depending on your version of Outlook.
2. Double-click on your Exchange account.
3. On the Exchange Server Settings page, click More Settings.
4. Click the Connection tab.
5. Click Exchange Proxy Settings.
6. Under Proxy authentication settings, click NTLM Authentication in the Use this authentication when connecting to my proxy server for Exchange list.
7. Click OK two times. Click OK again in response to the prompt that you must restart Outlook for the changes to take effect.
8. Click Next, and then click Finish.
9. Restart Outlook.

[Snake08]

Before you switch to using NTLM authentication, you must verify with your administrator that NTLM authentication is permitted or even possible in your environment. Many firewalls and proxy servers will prevent successful NLTM authentication, whereas Basic authentication will work successfully.

If your firewall and proxy server support NTLM authentication, you can refer to the following article to achieve your goal. It also applies to Exchange server 2007.

You must provide Windows account credentials when you connect to Exchange Server 2003 by using the Outlook 2003 RPC over HTTP features.