在ubuntu 18.04上配置mantis bug库，配置的是腾讯的企业邮箱，邮件总是发送不出去，附上apache2 error.请大神指导，该怎么解决呢？

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我修改了/var/www/html/mantisbt/config/config_inc.php

$g_enable_email_notification=ON; 
$g_phpMailer_method = PHPMAILER_METHOD_SMTP; 
$g_smtp_host = 'smtp.exmail.qq.com';
$g_smtp_username = '本人邮箱';
$g_smtp_password = '三方授权密码';
$g_webmaster_email = '本人邮箱';
$g_from_email = '本人邮箱';
$g_return_path_email = '本人邮箱';
$g_smtp_port = 465;
$g_administrator_email    ='本人邮箱';
# $g_from_name = 'Mantis Bug Tracker';
# $g_email_receive_own = OFF;
# $g_email_send_using_cronjob = OFF;

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/var/www/html/mantisbt/config_defaults_inc.php

$g_administrator_email    ='本人邮箱';
$g_webmaster_email         ='本人邮箱';
$g_from_email              ='本人邮箱';
$g_return_path_email    ='本人邮箱';
$g_enable_email_notification    = ON; 
$g_phpMailer_method       = PHPMAILER_METHOD_SMTP; 
$g_smtp_host              ='本人邮箱';
$g_smtp_username='本人邮箱';
$g_smtp_password= '三方授权密码';
$g_smtp_port= 465; 


查看/var/log/apache2/error.log
最后一条是：
[Wed Apr 24 10:29:42.972517 2019] [php7:error] [pid 706] [client 192.168.2.37:52663] PHP Fatal error:  Uncaught PHPMailer\\PHPMailer\\Exception: SMTP Error: Could not authenticate. in /var/www/html/mantisbt/vendor/phpmailer/phpmailer/src/PHPMailer.php:1960\nStack trace:\n#0 /var/www/html/mantisbt/vendor/phpmailer/phpmailer/src/PHPMailer.php(1774): PHPMailer\\PHPMailer\\PHPMailer->smtpConnect(Array)\n#1 /var/www/html/mantisbt/vendor/phpmailer/phpmailer/src/PHPMailer.php(1516): PHPMailer\\PHPMailer\\PHPMailer->smtpSend('Date: Wed, 24 A...', 'The user admini...')\n#2 /var/www/html/mantisbt/vendor/phpmailer/phpmailer/src/PHPMailer.php(1352): PHPMailer\\PHPMailer\\PHPMailer->postSend()\n#3 /var/www/html/mantisbt/core/email_api.php(1391): PHPMailer\\PHPMailer\\PHPMailer->send()\n#4 /var/www/html/mantisbt/core/email_api.php(1216): email_send(Object(EmailData))\n#5 /var/www/html/mantisbt/core/email_api.php(2019): email_send_all()\n#6 [internal function]: email_shutdown_function()\n#7 {main}\n  thrown in /var/www/html/mantisbt/vendor/phpmailer/phpmailer/src/PHPMailer.php on line 1960, referer: http://192.168.2.249:8050/manage_user_edit_page.php?user_id=5