two questions ( php.ini and mail)

[anakadote]

hi. when i run phpinfo() it lists the path to the php.ini file but the directory it says it's in is not present on my web server. how do i access it?

secondly, i have a mail form set up that works perfectly when i have it set up to send an email to my address, but when it's set up to send the email to a valid address on that mail server, it fails, giving this error, and i've been looking through previous posts and haven't found a solution:

a--Registeredsite Postmaster

----- The following addresses had permanent fatal errors -----
<[e-mail]>
(reason: 575 [e-mail] sender requires
authentication)

----- Transcript of session follows -----
... while talking to mail.address.com.:
MAIL From:<[e-mail]>
<<< 575 [e-mail] sender requires authentication
554 5.0.0 Service unavailable

[Kudose]

1. If your using windows, check to make sure that the path isnt in a hidden folder.

2. I think your mail problem has to do with SMTP AUTH.

http://en.wikipedia.org/wiki/SMTP-AUTH
http://www.eudora.co.nz/relay.html

[anakadote]

im using OS X. isn't php.ini located on the web server?

smtp authentication seems like the issue, im wondering if there is something we can turn off on the mail server or if there is authenticating code i need to include in the script to solve this?

thanks