HOTMAIL - Bounce Message Error Codes
These error codes apply to recipients with hotmail, live or outlook.com domain names.
Error codes starting with 4xxx are temporary problems. Error codes starting with 5xxx are permanent / fatal errors:
Fatal error: Uncaught Error: Call to undefined function mysql_connect() in /domains/smtp-error-codes.info/public_html/includes/mysql_conn.inc:2
Stack trace:
#0 /domains/smtp-error-codes.info/public_html/bounce_error_codes_hotmail.php(42): include()
#1 {main}
thrown in /domains/smtp-error-codes.info/public_html/includes/mysql_conn.inc on line 2