My ISP has port 25 blocked. I tried using Hotstop Shield to get around it, but the server identifies the proxy as spam'er. Where do I go from here?
There's no need to use a proxy. You can connect to Hotmail's mail server using the well-known port 587 (e-mail message submission).
Your ISP shouldn't block port 587, since it's intended specifically to submit a mail to a mail submission agent. Meanwhile, connections to port 25 could be used to send spam directly from your computer.