Why Outlook sometimes fails to find an email address

Ever had Outlook refuse to offer an email suggestion when you enter a contact name? Learn why, and how to work around this limitation.

When you begin an address in the To control, Outlook's AutoComplete feature will attempt to find the address for you. Some of us depend on this feature heavily, so it's annoying when Outlook fails to work as expected. We've all had it happen. We enter an address that we know is in our address book, but Outlook simply refuses to recognize it.

This happens after you've entered an email address, but before you've actually used it the first time. Outlook's AutoComplete feature only works with used addresses. That means, the first time you enter it in the To control, Outlook ignores it, because it's not in the AutoComplete list yet-Outlook will add it the first time you use it. Simply adding an address to the address book isn't enough.

Consequently, the first time you use the address, you must have it committed to memory or click the To control to open the address book so you can find it. Neither solution's ideal.

Fortunately, Outlook offers a quicker solution: type the Display As name, as you normally would, but don't press Enter; instead, with the cursor at the end of the entry, click Check Names in the Names group on the Message tab (or press [Ctrl]+k). It works like a charm! The next time you need the address, it'll be in the AutoComplete list and Outlook will suggest it.

If Outlook displays the Check Names dialog box when you click Check Names, there's no address for your entry or there's more than one entry for your entry. Clicking Check Names forces Outlook to resolve your entry against the names of all other users in your address list.


Susan Sales Harkins is an IT consultant, specializing in desktop solutions. Previously, she was editor in chief for The Cobb Group, the world's largest publisher of technical journals.


Just populate the To: field with everyone in your address book, wait 10 to 15 seconds and cancel/close the New email window. Next time you send an email the To: field will auto populate. If you have 100's of contacts just select the first contact, scroll all the way to the bottom of list, hold shift and click on the contact.

Paul R M
Paul R M

The other side of the problem is that an outdated address will come up from the AutoComplete feature, so that even though you've changed your address book to the new address it tries to send it to the old one. The only solution I've found is to delete the old entry from the list that pops up and make it "Check Names" to find the corrected one. Is there a way to update the whole AutoComplete list?


Delete and recreate your nk2 file. Make sure you've made a backup of the file first.

Editor's Picks