I am trying to configure email notification on Mantis which is on windows server MySQL database. I am using below configuration:

###########################

MantisBT Email Settings

###########################
#$g_webmaster_email = 'webmaster@example.com';
$g_from_email = 'osha@hunterconsulting.com';
$g_from_name = 'OSHA';
$g_return_path_email = 'dhansaliya@hunterconsulting.com';
$g_enable_email_notification = ON;
$g_email_notifications_verbose = OFF;
$g_default_notify_flags = array(
'reporter' => ON,
'handler' => ON,
'monitor' => ON,
'bugnotes' => ON,
'category' => ON,
'explicit' => ON,
'threshold_min' => NOBODY,
'threshold_max' => NOBODY
);
$g_notify_flags['new'] = array(
'bugnotes' => OFF,
'monitor' => OFF
);

$g_notify_flags['monitor'] = array(
'reporter' => OFF,
'handler' => OFF,
'monitor' => OFF,
'bugnotes' => OFF,
'explicit' => ON,
'threshold_min' => NOBODY,
'threshold_max' => NOBODY
);
$g_email_receive_own = OFF;
$g_validate_email = ON;
$g_email_ensure_unique = ON;
$g_check_mx_record = OFF;
$g_allow_blank_email = OFF;
$g_limit_email_domains = array();
$g_show_user_email_threshold = NOBODY;
$g_show_user_realname_threshold = NOBODY;
$g_phpMailer_method = PHPMAILER_METHOD_SMTP;
$g_smtp_host = 'MY_SMTP_SERVER';
$g_smtp_username = 'username@MY_SMTP_SERVER';
$g_smtp_password = 'my SMTP_SERVER_PASSWORD';
$g_smtp_connection_mode = 'tls';
$g_smtp_port = 25;
$g_email_send_using_cronjob = OFF;
$g_email_separator1 = str_pad('', 70, '=');
$g_email_separator2 = str_pad('', 70, '-');
$g_email_padding_length = 28;

and I am getting following error. I not sure what I am doing wrong. I will really appreciate if you guys can help me.

Thanks

2017-04-10 11:11 EDT MAIL email_api.php:974 email_bugnote_add() Note ~18 added to issue 0000001
2017-04-10 11:11 EDT RECIPIENT email_api.php:280 email_collect_recipients() Issue = 0000001, add @U2 (reporter)
2017-04-10 11:11 EDT RECIPIENT email_api.php:290 email_collect_recipients() Issue = 0000001, add @U1 (handler)
2017-04-10 11:11 EDT RECIPIENT email_api.php:344 email_collect_recipients() Issue = 0000001, add @U1 (note author)
2017-04-10 11:11 EDT RECIPIENT email_api.php:427 email_collect_recipients() Issue = 0000001, drop @U1 (own action)