With Dynamic DNS you can easily run a mail or web server on a home broadband connection even though your IP address may change periodically.
Simply install one of the many dynamic DNS clients on your server, or configure any router with a built-in dynamic DNS module and you're good to go.
ISP blocking port 25? Don't worry, you can also setup SMTP port forwarding (requires DNS Pro level service) to workaround that. You can also use our outbound SMTP service to relay your mail out.
(But don't even think about spamming!)