I recently tried to email different people with yahoo.com email addresses individual emails and got this message , "email not accepted for policy reasons"? Is this because I am sending them an email with my domain as the return address? So they are essentially censoring emails to their users if it appears it is coming from a adult domain? 
Final-Recipient: rfc822; <"Recipient"@yahoo.com>
Action: failed
Status: 5.1.0 MAIL FROM: <
[email protected]> 554 REPLY: 554_Message_not_allowed_-_UP_Email_not_accepted_for_policy_reasons.__Please  _visit_http://help.yahoo.com/help/us/mail/defer/defer-04.html_[120]
Diagnostic-Code: smtp; Permanent Failure: Other address status
Last-Attempt-Date: Thu, 14 Aug 2008 18:22:10 -0000