All versions of Outlook support automatic name checking, also known as Autoresolve. This feature allows you to type a name, or even just the first few letters, and the name resolves a few seconds after you tab out of the field. When one match is found, the name has a solid underline. When more than one possible match exist you’ll see a red wavy underline. Right click on it to choose an address. When more than one match exists for a name you’ve used before, Outlook resolves to the last name used and uses a green dotted line to alert you that other possibilities exist. Right click to see the other addresses.

Autocomplete is the feature that shows addresses of people you’ve sent messages to previously and you can select matches as you begin typing. Autocomplete collects the addresses when you send new messages or reply. You can clear the autocomplete cache by clearing the autocomplete cache or delete one address at a time as you type and then Delete.

See Understanding Outlook’s Auto-Complete Cache for more information.

How to use Automatic name checking:

1. Start a new message.
2. Type the text you want to use for the nickname into the To box.
3. Fill in the subject and start typing a message.
4. When you see the name in the To box underlined with a red squiggle, right-click on the name. You'll see a choice of matching names from your address book. Choose the one you want to use. If the contact you want is not listed, press Ctrl+K to bring up the Check names dialog then click More Names to browse for the correct contact.

The next time you want to send a message to that person, just type in the text from Step 2 again. Outlook will automatically get the address for you and will underline the full name in a dashed green line to highlight that auto-resolution did its job.

There is one limitation that "gets" many users: when you use auto-resolution, Outlook searches the address books in order and when it finds a match in one address book, it stops looking in the other address books.

Autoresolution or Automatic name checking

All versions of Outlook support Autoresolve. Also known as automatic name checking, this feature allows you to type a name, or even just the first few letters, and the name resolves a few seconds after you tab out of the field. When one match is found, the name has a solid underline. When more than one possible match exist you'll see a red wavy underline. Right click on it to choose an address. When more than one match exists for a name you've used before, Outlook resolves to the last name used and uses a green dotted line to alert you that other possibilities exist. Right click to see the other addresses. When Name checking is disabled in Tools, Options, Email Options, Advanced Options it won't do it as you type the names in but it will check and resolve them when you hit Send. You can force an autoresolve at anytime using Ctrl+K.

Here's some additional information on how multiple address lists, including the GAL, affect the resolution process.

What fields does Outlook use to look up names for address resolution? It depends on the address list. For the Exchange Global Address List (GAL), it searches several fields -- display name, surname, mailbox alias and office (but, significantly, not first name).

For Contacts and Personal Address Book, the search fields include name and email address fields, but *not* the Nickname field on contacts.

Name resolution searches only one address list at a time. Use the Address book's Tools, Options dialog to control the order in which lists are searched in Outlook. Let's say you have the GAL set as the first list, followed by more than one Contacts folder. If there are matches in the GAL, you won't see any addresses from Contacts. If there is no match in the GAL, then it searches the first Contacts folder in the list. If no matches in that contacts folder, then it searches the next Contacts folder. If you think about performance, this makes a lot of sense. Searching across all address lists in your name resolution list could take a very long time.

For example, entering "William" and pressing Ctrl+K might display a list that includes William Gates, Bart Williamson, and Jane Williams. If there are no matches in the GAL for William, then you might also get names from the PAB with addresses like williamg@domain.dom. The search is always a "starts with" search, looking only at the beginning of the fields. It would not find a name like Alice Fitz-Williams because "Williams" here is not at the beginning of the surname.

Disable Automatic name checking and/or AutoComplete

To change the Autocomplete or Automatic name checking settings in Outlook 2010 and newer, go to File, Options, Email and scroll to near the end.

If Automatic name checking is disabled, Outlook will still resolve the names when you send the message, but not immediately. You can force Outlook to resolve the names by pressing Alt+K on your keyboard.

In Outlook 2007 and older, you can disable autoresolution in Tools, Options, E-mail Options, Advanced E-mail Options, Automatic name checking. When this is turned off, Outlook will still resolve the names, but not immediately. You can press Alt+K to force auto-resolution at any time before sending the message; otherwise Outlook will always resolve the address when you send the message. If a match isn’t found, you’ll be asked to pick names using the Check Names dialog.

To disable Auto-complete in Outlook 2007 and older, go to Tools, Options, Preferences, E-mail Options, Advanced and deselect ‘Suggest names while completing to To, CC, BCC fields’

The following tools can be used to view the contents of the auto-complete cache.