If you have Contacts in the Contacts folder but they are not accessible when you click on the To button, and they were not imported, see Outlook Contacts are missing when you click the To button for a common problem affecting Microsoft Outlook.

Addresses imported into the Contacts folder may not appear in the Address Book display and may not show all fields when Inserting Addresses in Microsoft Word Documents.

This happens because the e-mail address has not been "resolved," using the Check Names function. Resolved addressees are underlined in the E-mail fields in the Contacts record.
resolved contact address

Open each contact and click the Check Names button on the ribbon, or click in the address field and press Ctrl+K should resolve the addresses or you can use a macro to automate the process.

As written, this macro runs on the default contacts folder in your Outlook profile.

Resolve Addresses using VBA

Public Sub ResolveEmailAddresses()
Dim objOL As Outlook.Application
Dim objNS As Outlook.NameSpace
Dim objContact As Outlook.ContactItem
Dim objItems As Outlook.Items
Dim objContactsFolder As Outlook.MAPIFolder
Dim obj As Object
Dim olRecip As Recipient
'  On Error Resume Next

Set objOL = CreateObject("Outlook.Application")
Set objNS = objOL.GetNamespace("MAPI")
Set objContactsFolder = objNS.GetDefaultFolder(olFolderContacts)
Set objItems = objContactsFolder.Items

For Each obj In objItems
'Test for contact and not distribution list
  If obj.Class = olContact Then
    Set objContact = obj

    With objContact
'Email1
    Set olRecip = objNS.CreateRecipient(.Email1Address)
      If olRecip.Resolve Then
        .Email1Address = olRecip
        Debug.Print olRecip
      Else
        MsgBox .Email1Address & " Not resolved"
      End If

'For Email2
    Set olRecip = objNS.CreateRecipient(.Email2Address)
      If olRecip.Resolve Then
        .Email2Address = olRecip
        Debug.Print olRecip
      Else
        MsgBox .Email2Address & " Not resolved"
    End If

'For Email3
    Set olRecip = objNS.CreateRecipient(.Email3Address)
      If olRecip.Resolve Then
        .Email3Address = olRecip
        Debug.Print olRecip
      Else
        MsgBox .Email3Address & " Not resolved"
      End If

    End With
  End If

Err.Clear
Next

Set objOL = Nothing
Set objNS = Nothing
Set obj = Nothing
Set objContact = Nothing
Set objItems = Nothing
Set objContactsFolder = Nothing
End Sub

How to use the macros on this page

First: You need to have macro security set to the lowest setting, Enable all macros during testing. The macros will not work with the top two options that disable all macros or unsigned macros. You could choose the option Notification for all macros, then accept it each time you restart Outlook, however, because it's somewhat hard to sneak macros into Outlook (unlike in Word and Excel), allowing all macros is safe, especially during the testing phase. You can sign the macro when it is finished and change the macro security to notify.

To check your macro security in Outlook 2010 and newer, go to File, Options, Trust Center and open Trust Center Settings, and change the Macro Settings. In Outlook 2007 and older, look at Tools, Macro Security.

After you test the macro and see that it works, you can either leave macro security set to low or sign the macro.

Macros that run when Outlook starts or automatically need to be in ThisOutlookSession, all other macros should be put in a module, but most will also work if placed in ThisOutlookSession. (It's generally recommended to keep only the automatic macros in ThisOutlookSession and use modules for all other macros.) The instructions are below.

The macro on this page should be placed in a module.

Open the VBA Editor by pressing Alt+F11 on your keyboard.

To put the code in a module: