hello friends!
a kind request from me to solve my problem!

i was infact trying to forge an e-mail.I connected to my outgoing SMTP address and i did the following:

telnet xxx.xxx.xxx 25 (i did)
220 xxxxxxxxxx ESMTP
helo user (i did)
xxxxxxxxxxxxxx OK
mail from: xxx.yahoo.com (i did)
Address OK
rcpt to: xxx.xxx.xxx (i did)
Relaying not allowed xxx.xxx.xxx


THAT IS MY PROBLEM!
please tell a way to hack into the server and to prevent this message! "relaying not allowed". PLEASE!!!!!!!!