Deployment How-To ARchive WHMCS can't send mail through Yandex via SMTP
The symptom
WHMCS v7 is installed on server running CentOS 6.10/cPanel v70/PHP 7.1 and configured to send mail via SMTP using PHPMailer through Yandex mail server. Trying to send mail results in error:
Email Sending Failed - SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting …