Hi, Problem is realted to your smtp server. Make sure it allowed outgoing mail without authenctication. You must also set a header in fourth parameter of mail function, it is good practice and can save you from some basic indentification problems. In windows you can set default send mail from in php.ini Try Mail("you@xxxxxxxxxxxxxx","test subject","test body","from:your_email@xxxxxxxxxxxxxxxxxxxxx\r\r"); If it fails contact your ISP. Additionally read http://www.chilkatsoft.com/faq/Smtp550.html Zareef ahmed -----Original Message----- From: Garth Hapgood - Strickland [mailto:garth@xxxxxxxxxxxxxx] Sent: Wednesday, November 10, 2004 6:06 PM To: php-general@xxxxxxxxxxxxx Subject: php mail() error Im using the php mail() function to try send an email to a user that has just registered. mail($HTTP_POST_VARS['emailaddress1'], 'Matchmakers Website Registration' , 'Welcome'); But when I get the following error back.: Warning: mail(): SMTP server response: 550 5.7.1 Unable to relay for garth@xxxxxxxxxxxxxx Can someone help me out, by telling me what it means or what Im doing wrong? Thanx Garth ------------------------------------------------------------------------ -- Zareef Ahmed :: A PHP develoepr in Delhi ( India ) Homepage :: http://www.zasaifi.com -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php