Hello,

When users are prompted for credentials in Outlook (for example, password was changed), the username field is filled out with e-mail address in format firstname.lastname@company.com instead of UPN that is in format like firstname first letter and lastname and the suffix company.net

Thus being said, Primary E-mail address for the mailbox is different from the UPN.

Please advise why this happen and how it is possible to configure Outlook for filling the UPN instead of e-mail address.

Outlook users are foolished by wrong autocomplete in Outlook credentials prompts window and end up in filling a lot of calls to IT support

Details about the environment:

Active Directory, Exchange 2013, Outlook 2013

T

Hi,

Please either change UPN to the same as SMTP address to fix this issue, or change email address to same as user name to fix this issue.

If the email address is different with the UPN, it would firstly authenticate the domain user account with Activity Directory credential. If the windows account can be used for AD authentication. Then the credential window would pop up in Outlook for the Exchange mailbox (email address) authentication.

Additionally, here is a similar thread for your reference:

http://community.office365.com/en-us/f/613/t/66166.aspx

Regards,

Hi Winnie Liang,

thanks for answer, after matching UPN to external e-mail the issues is not appearing. However, there are some caveats in matching UPN to e-mail address in large AD organizations:

1) UPN is already used in many other systems for authentication (internal HR, internal asset management, etc)

2) e-mail address is externally available to the world and cannot be changed

Thanks,

Andrei