SMTP server response: 553 We do not relay non-local mail

[oculus]

Hi,

Anybody here knows why I can't send mail to my Yahoo! account? I'm working on the registration script and tried to register a user with Yahoo! account; however, XAMPP says,

Warning: mail() [function.mail]: SMTP server response: 553 We do not relay non-local mail, sorry. in C:\xampp\htdocs\phplogin\register.php on line 60

Question: Why? and What should I do? Responses would be greatly appreciated; suggestions, too!

[Wiedmann]

You must configure your smtp server and allow mail relaying.

[oculus]

Oh, thank you for that suggestion. I appreciate it so much!
But I don't have a clue to configure my SMTP server and allow mail relaying.
How do I configure my SMTP server and allow mail relaying?

[oculus]

Okay now...
I get no more errors. XAMPP says,

Registration Successful! An activation code has been sent to your email address with an activation link...

But when I checked my Yahoo! mail, I wasn't able to see it. Was there anything wrong happened or the configuration per se seems to be "incorrect"?

[Wiedmann]

But when I checked my Yahoo! mail, I wasn't able to see it.

Did you have any log in your mailserver? Or a mail in your mail directory?

BTW:
Which SMTP server are you using? A local one, or one at your ISP?

[oculus]

Wow! Thanks for the speedy response!...

As to your question, NO. I don't have any log in on my mailserver or a mail in my mail directory. In addition to your question, I'm using Mercury/32. And actually, I don't get it,

A local one, or one at your ISP?

[oculus]

What possble actions I can take to get the message in my Yahoo! mail? Am desperate