I want to send a copy automatically to my yahoo.com email account.
While what Bob saus is true, it would be more efficient to do the
autoforwarding from the server. if you can. If this is a home user, log into
your mail account via web browser and see if there are any autoforwarding
options available. If you autoforward with Outlook, chances are excellent
you'll need to have Outlook running all the time in order to perform the
forwarding.