Send Email From Local Machine

I have a HelpDesk query form that sends an email to the helpdesk with a users problem. I'm trying to test this on my local machine but each time I get to the mail() code it returns the below error.

"Warning: mail(): SMTP server response: 451 See http://pobox.com/~djb/docs/smtplf.html. in ......."

I went to the link and read some emails to addresses like msn.com might not get through but I sent an email to myself and it still returned the error message.

Can anyone offer some suggestions?

Thanks. :confused:

Well the definition of the 451 error from RFC 821 is as follows:

451 Requested action aborted: local error in processing

It looks like there is a problem with the server. Have you checked your PHP.ini to ensure that you have the SMTP directive pointing to you ISP's SMTP server?

If you're doing this locally... do you have a SMTP server installed?? If so, is it working? I had this problem too a while ago, until I realized that I never setup any kind of mail server on my computer. I still haven't... I just use my ISPs now.