Unable to send mail by smtp.zoho.com - Reason: Connection could not be established with host smtp.zoho.com

Unable to send mail by smtp.zoho.com - Reason: Connection could not be established with host smtp.zoho.com

Connection could not be established with host smtp.zoho.com [Connection timed out #110] {"userId":6,"email":" *********@chinafinance.pro ","exception":"[object] (Swift_TransportException(code: 0): Connection could not be established with host smtp.zoho.com [Connection timed out #110] at /var/www/html/chinafinance/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Transport/StreamBuffer.php:269)