Hello, I understand Yahoo will give you an e-mail address [email]reportabuse@cc.yahoo-inc.com[/email], or either [email]reportabuse@yahoo-inc.com[/email] one or the other works, I rememeber I tried both when I had my e-mail being blocked, you can also go to help.yahoo.com and type in the search, why is my e-mail being blocked? it might be able to answer how to request for your e-mail to be unblocked.

Hope this helps