My hosting company disallows smtp mail relay on our mail server even with an email address coming from and to the domain. I was wondering what alternatives I can use to automate emails on my asp.net application.

I have a user registration form. I usually use a sendEmail method i wrote in C# that relays a created mail message to a user and the site admin. Since i can't relay i i was wondering what else i could use?

Thanks in advance.
mcm