Instant messaging software makes speaking to your friends quick, easy and convenient. Yahoo Messenger, for example, works on both computers and mobile devices; you can have your conversations anywhere. If you don’t know the Yahoo ID of the chat contact you want to add to your list but you do know the person’s email address, you may be able to use that. If the person you’re searching for used an email address to register for Yahoo Messenger, they’ll be added to your list when you search with it. Tips Writer Bio