Outlook/Exchange username not found / Name cannot be match to a name in the address list

By : Sean Brown |December 08, 2011 |Microsofft Exchange Server, Microsoft Office, Windows Server |2 Comments

As we all [should] know, Exchange 2000, 2003, 2007 and 2010 rely on and require active directory to operate; While Exchange server may be a scary application for a junior/mid-level admin, there is one particular issue which I have experienced all the way back to Exchange 2000 which can trip-up even the most senior, well seasoned administrator (i’m not going to lie – this one got me many years ago).

Problem: When settting up Outlook, “The name cannot be resolved.  The name cannot be match to a name in the address list” error message is displayed.

Background: Most Exchange-knowledgeable admins realize that once the “Check name” box is clicked, a query is sent (behind the scene) to active directory to locate the user object, which then resolve/return which exchange server is user has a mailbox on.  Once the user account is queried on the Exchange server and validated/authenticated, the username becomes Underlined and everything works.

Typically when Active Directory issues occur or a AD/GC server cannot be contacted, the “check name” validation will fail.  Where this issues becomes tricky is that Outlook doesn’t handle this error too well in the sense of troubleshooting.  There are virtually no diagnostics at this screen which tell you if:

  • Connectivity to AD/GC failed
  • Connectivity to the Exchange/SA failed
  • User account issues (directory or security)



Where things get complicated:  Exchange has a really cool feature of Global Address lists, meaning anyone who is inside of the Exchange organization will automatically be added into an Active Directory/Exchange managed list and this will be automatically distributed to all Outlook clients.

Admins also have a nifty-check box to “Hide from Global Address list,” meaning that you can hide group mailboxes, service mailboxes or non-critical mailboxes from the GAL. Advanced admins have the ability to segregate Global Address Lists (GAL) and display certain lists for certain users (example: if one organization has multiple companies and in-turn only want to display the GAL for which that user works for).

Where things get VERY complicated is the fact that Outlook’s  lack of diagnostics during the account setup process can leave the most experienced admin searching for problems when there are none.

Why things appear to be broken:  Even though Outlook queries active directory for the object and finds an exchange server, the user can only be validated (initially) IF they appear in a Global Address List.

  • If you have a custom GAL, you need to make sure that the user appears in a specific GAL, if they don’t – they won’t resolve in Outlook.   If you have custom GAL’s, do queries on the list and verify that the user account exists in at least one GAL.
  • If you have checked “Hide from Global Address List,” they won’t resolve in Outlook. Simply uncheck “Hide from Global Address List” and re-resolve – it will work.


About Sean Brown

Sean Brown is a seasoned IT/Telecommunications professional working in the sector since the mid/late 90′s. Learn more about Sean by viewing his professional biography and Resume/CV.


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