Hi,
I will check the issue and will fix by installing SSL on site to make it secure and also will resolve postfix issue by updating all required records like SPF, DKIM, Dmarc etc to make it running.
I have 8 years of experience and knowledge as system administrator, setup and management of different Linux Web Hosting Servers, Cloud Servers, Server Monitoring, Server Security, Server Optimisation, Mailing Servers, Email Marketing, SSL, DNS, Apache, Nginx, etc with Cpanel, Plesk, Virtualmin or other panels.
Services such as cPanel/WHM, Plesk, Virtualmin LAMP Stack, Tomcat, Mysql/MariaDB, Zimbra, Postfix mail server, Mailenable, smarter mail, MSSQL, etc.
Let's discuss.
Thanks !