VITCIE info: Can not connect to MySQL server

Time: 2023-1-19 2:50am
Script: /classroomviewdoc.php

Error: Unknown MySQL server host 'hdm-011.hichina.com' (1)
Errno.: 2005

An error report has been dispatched to our administrator.
Fatal error: Call to undefined function sendmail() in /usr/home/hyu3102420001/htdocs/include/db_mysql_error.php on line 51