You should be able send mail through your ISP's outgoing (SMTP) mail server. Most ISP's allow you to send messages regardless of the return/sender's address. So in essence you could have your return address as "Billy Gates" <Bill_Gates@microsoft.com> and still use your ISP's outgoing server to send mail. Besides the headers, your message won't get altered. You will need to reference to your ISP for this information.