Eu fui ao Yahoo Messenger, depois cliquei em Messenger e em "Informações da minha conta"
Eu então peguei esta página
Você deseja clicar em Gerenciar aliases do yahoo. Não é o mesmo que os aliases do Yahoo nas opções de e-mail.
Depois de adicioná-los, você pode fazer login como qualquer um, ou em uma janela de bate-papo logo acima de onde você digita uma mensagem, você pode escolher "enviar como" e escolher qualquer um deles.
Profile Information
Edit profile details <--- not this oneContact Information
Update your contact information <--- not this one Choose how Yahoo! contacts you
Login e segurança
Change your password Update password-reset info Create a sign-in seal Manage/Create your OpenID Manage Other Accounts to Sign-in Manage Apps and Website Connections Change sign-in settings View your recent sign-in activity
Account Settings
Manage your Yahoo! aliases <---- THIS ONE
View/Update your saved locationsNotifications and Subscriptions
View your Yahoo! premium services.
Update newsletter & marketing options
A resposta aqui funcionou para mim link
Click on "Account Info" which is in the drop down menu (on your email page) by your username where it says "Hi, ____".
Sign into your Yahoo Account. Go to the section "Account Settings" and click on "Manage your Yahoo Aliases".
Click on "Add an Alias". Type your alias in the box provided and then click on "Save". You can have up to 6 aliases. Click on "Close when finished".
In the Messenger Pane, click on "Contacts" and then "Add a Contact" and add your aliases to your Yahoo Messenger. (You don't need to do this).
When you IM someone, pick the name you want to use in the drop down box above where you type next to "Send As".
Here is a link telling you how to use one of your aliases when you enter Chat Rooms.
http://help.yahoo.com/kb/index?y=PROD_MS…
Alternatively, you could just change your current name by changing your Contact Details. To do this, click on "Messenger" in the top left hand corner of the Messenger Window. Click on "My Contact Details" and change your name in the top boxes and change your name under "Nickname". Click on "Save and Close" at the bottom.