If you have just set up your own email domain and are using your ISP or another 3rd party to host it is  likely that your email will get rejected by several of the larger mail operators notably hotmail and AOL. This is because your domain record lacks an SPF record which allows other email servers to know that your email is coming from a valid server. Your domain record hoster (such as godaddy) may offer an easy to use tool to create the SPF record if not then this tool HTTP://old.openspf.org/wizard.HTML will help you build a syntactically correct record which you can test by sending an email to check-auth@verifier.port25.com who will validate that you have set it up correctly.