Failed to connect to mailserver with IIS

Hello, I installed PHP4.3.10 on IIS/win2000! The settings in php.ini is correct, I use the same smtp for my e-Mail dddresse in Outlook-Express and it work fine without authentification. So, the problem must be a PHP-Problem. Do anybody know the solution of this problem? Is there a way to get a better error message then this: Warning: mail(): Failed to connect to mailserver at "smtp.freesurf.ch" port 25, verify your "SMTP" and "smtp_port" setting in php.ini or use ini_set() in E:\test_mailtest.php on line 9 Thanks pw