As previously posted, you need to work with your mail server admin. sendmail is not normally on WinDoze boxes, so do some googling for the setup you have, and talk with your admins to see what you need to do to get it set up to work correctly. Wolf Diana wrote: > I have tried settiing my php.ini to > SMTP = localhost > as well as using the SMTP of my regular mail, and I keep on getting this. > Warning: mail() [function.mail]: SMTP server response: 550 5.7.1 Unable to > relay for dcastillo@xxxxxxxxxxxxxxx in C:\Inetpub\wwwroot\intranet\test.php > on line 11 > -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php