SMTP through telnet

help required,
i am trying to show how to telnet into a mail server and create mails for sending, and also how to retrive mails from mail servers. most mail service providers do not support relaying. hence i cannot readily send emails by using a telnet session and using SMTP commands.
can anyone suggest me a mail service where they do support relaying, so that i can demonstrate how SMTP commands work?

If you've got internet access at home, you should be able to telnet into your ISP's SMTP servers.

yes i have internet connection and i am using that to telnet into my smtp servers, it logs in but once i try to send a mail, after the RCPT TO command it says "RELAYING NOT ALLOWED"
any idead?

Some ISPs rely on client IPs for authentication, while others rely on a user name or password. If your ISP belongs to the second group, you will need to use the AUTH command.

hi,
i am using my ISP provided IP when i am trying to put the HELO command. that comes up good, and it recognizes me. but the moment i try to put the RCPT command, it starts giving off the relaying stuff, and that it does not allow relaying.
i have tried the AUTH command to get around it. but no joy