PHP uses SMTP to send mail error cannot connenct to relay host

Use dedecms to customize a mail to send the PHP file, using the dedecms of the mail.class.php, local can be sent, upload to the server, appear prompted cannot connenct to relay host Smtp.qq.com Error: () error:cannot send email to XXX@qq.com online Find a lot of articles, finally resolved, the problem is in the server's environment configuration.

Find PHP.ini, look at two places, one is Allow_url_fopen, this place is set to on, and the other is to view the disable_functions, if Fsock,fsockopen appears later, you need to remove the two functions, Restart Apache, and then you can send the message normally