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Outlook continually prompting for username and password

Glen KnightLead Techical Consultant
There have been a lot of questions recently regarding Outlook prompting for a username and password whilst using Exchange 2007. There are a few reasons why this would happen and I will try to cover the most common ones here.

Exchange 2007 Service Pack

There was an issue with repeated password prompts that was resolved by installing Rollup 9 for Exchange 2007 SP1, however I would recommend that you should now be using Exchange 2007 SP2 since it has been around since August 2009: Exchange 2007 Service pack 3 is also available:

If you are in an Small Business Server 2008 environment and not yet using Exchange 2007 Rollup 9 you can also install SP2 for Exchange 2007 with the aid of the Installation Tool, available here:;EN-US;974271


If that doesn’t fix the repeated prompt for password then it could be down to the autodiscover if you are using Outlook 2007 then you must configure autodiscover correctly. There are many articles out there that cover the correct way to configure autodiscover, one of the better ones I have found is this one:

However the part that most people are missing is the (where is the part after the @ in your e-mail address. Newer versions of outlook will look for this for OAB download, free/busy information, Out of Office etc etc. If it’s not there then outlook will continually give user prompts. To accompany this you must have an SSL Certificate that contains the URL (whilst you can configure ways around this, it really isn’t worth all the hastle). So purchasing an SAN/UCC Certificate, which you can get from with the following names in is a must for Exchange 2007 and Exchange 2010: (the URL used for Outlook Web Access) (used in SBS 2008)
servername.domainname.local (the internal FQDN of your Exchange Server)
SERVERNAME (NETBIOS Name of your Server)

You must also have the corresponding and A records configured in your external DNS

Kernel authentication Mode

If you have all the above configured and you are still experiencing problems then the following procedure will more than likely fix it for you. It has been working a lot for me lately and also for people asking questions on Experts Exchange.

In Internet Information Services (IIS) Manager locate the Exchange virtual directories, if you are using Small Business Server 2008 these will be under the SBS Web Applications website, if you are not using SBS then they will be under the Default Website.

The virtual Directories you are looking for are:


In turn highlight each of these virtual directories and double click the Authentication icon on the right hand side. Right click on Windows Authentication and select Advanced Settings. Place a check box in the box for Enable kernel-mode authentication. Do this for each virtual directory listed above.

Internet Explorer Proxy

Another recent discovery is that if you use a proxy server then you need to ensure that the exchange servers fully qualified domain name is in the exclusion list.

This can be done manually in Internet Explorer under Tools > Internet Options > Connections or using Group Policy if you want to make the change in a centralised environment.

Hopefully some or all of the above changes will stop the repeated password prompts from appearing and your users from getting frustrated.
Glen KnightLead Techical Consultant

Comments (66)

There is also a known issue where, if using Outlook, the profile is just corrupt.
This typically means only one user out of a group will continuously be prompted for passwords.
Either the Outlook profile or the Credentials Manager is corrupt.
Creating a new Outlook profile from scratch will probably fix this, else delete stored credentials for e-mail and recreate them. There are tools out there to clean up Outlook profiles and credentials most notably OutlookProfileCleaner.exe
Ricardo MartínezInformation Security

I have the same problem but in Exchange Server 2010 & Microsoft Outlook 2010, do this suggestions work on this environment? can someone suggest me where to look up for this problem?

i have the same problem: outlook 2010 and exchange 2010 on my vpn users only.
checked the credential manager side of things.
same problem.

i think its since UR7 for exchange...

IT GuySys Admin/Windows Admin

Does this also work for Outlook 2013 using Office 365 or Exchange 2013 email servers

Or what is the process for fixing issues where Outlook continually prompts for a username and password within Outlook 2013?

What online resources or other Experts Exchange articles or solutions discuss this?

I think my issue (in the end) was that there was another device (active sync or 3rd party app installed within outlook) that was causing the problem.  also rebooting exchange helped.

not had problem since..

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