How do I access my old email address?

I have just taken delivery of BT broadband and it has wiped off my "My Yahoo" email which has a number of important messages on it. How do I recover them. This is most important

How do I access my old email address?
Was it pop3 (client like Outlook or Outlook Express) or webmail?





If the latter you can access it easily from http://mail.yahoo.com