New sign-up users can't recevie mail

[daisyapplegirl]

My project use Apache server 2.2 + Mysql 5.6.21 +Php5.3.2, Most important I use network public email server like gmail
I set the mail items in php configure file php.ini
1、SMTP = smtp.qq.com
2、smtp_port = 465
3、sendmail_from = mymail@qq.com
set mail items in mantis configure file config_inc.php as below
$g_administrator_email = 'mymail@qq.com';
$g_webmaster_email = 'mymail@qq.com';
$g_from_email = 'mymail@qq.com';
$g_from_name = 'Mantis Bug Tracker';
$g_return_path_email = 'mymail@qq.com'
$g_enable_email_notification = ON;
$g_phpMailer_method = PHPMAILER_METHOD_SMTP;

$g_smtp_host = 'smtp.qq.com';
$g_smtp_username = 'mymail';
$g_smtp_password = '123';
$g_smtp_connection_mode = 'ssl';
$g_smtp_port = 465;
No mail received, No logs can be check. I run test_email.php but No mail received. Hope someone can offer help, thx!