This example searches an Outlook contacts folder for a specific contact by first and last name. The example assumes that a contact named John Evans exists in the contacts folder.
Applies to: The information in this topic applies to application-level projects for Outlook 2013 and Outlook 2010. For more information, see Features Available by Office Application and Project Type.
Example
Private Sub ThisAddIn_Startup(ByVal sender As Object, _
     ByVal e As System.EventArgs) Handles Me.Startup
    FindContactEmailByName("John", "Evans")
End Sub 
Private Sub FindContactEmailByName(ByVal firstName As String, _
    ByVal lastName As String)
    Dim outlookNameSpace As Outlook.NameSpace = Me.Application.GetNamespace("MAPI")
    Dim contactFolder As Outlook.MAPIFolder = _
        outlookNameSpace.GetDefaultFolder( _
        Outlook.OlDefaultFolders.olFolderContacts)
    Dim contactItems As Outlook.Items = contactFolder.Items
    Try 
        Dim contact As Outlook.ContactItem = _
            CType(contactItems.Find(String.Format _
            ("[FirstName]='{0}' and [LastName]={1}", _
            firstName, lastName)), Outlook.ContactItem)
        If contact IsNot Nothing Then
            contact.Display()
        Else
            MsgBox("The contact information was not found.")
        End If 
    Catch ex As Exception
        Throw ex
    End Try 
End Sub
private void ThisAddIn_Startup(object sender, System.EventArgs e)
        {
            FindContactEmailByName("John", "Evans");
        }
        private void FindContactEmailByName(string firstName, string lastName)
        {
            Outlook.NameSpace outlookNameSpace = this.Application.GetNamespace("MAPI");
            Outlook.MAPIFolder contactsFolder =
                outlookNameSpace.GetDefaultFolder(
                Microsoft.Office.Interop.Outlook.
                OlDefaultFolders.olFolderContacts);
            Outlook.Items contactItems = contactsFolder.Items;
            try
            {
                Outlook.ContactItem contact =
                    (Outlook.ContactItem)contactItems.
                    Find(String.Format("[FirstName]='{0}' and "
                    + "[LastName]='{1}'", firstName, lastName));
                if (contact != null)
                {
                    contact.Display(true);
                }
                else
                {
                    MessageBox.Show("The contact information was not found.");
                }
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }