Error Send Test Email in Cpanel Whm

My Mautic version is: 3.3.3
My PHP version is: 7.3
My Database type and version is: MySQL 5.7

I use WHM/Cpanel v96.0.7 and Cloudlinux 7.9

My problem is: I’ve installed Mautic and cant sent test email, when I configure “Other SMTP Server” to send email using the same server I got the error. The ports are opened.

These errors are showing in the log:

Connection could not be established with host mail.yourbesdate.online :stream_socket_client(): php_network_getaddresses: getaddrinfo failed: Name or service not known Log data: ++ Starting Swift_SmtpTransport !! Connection could not be established with host mail.yourbesdate.online :stream_socket_client(): php_network_getaddresses: getaddrinfo failed: Name or service not known (code: 0)
++ Starting Swift_SmtpTransport !! Connection could not be established with host mail.yourbesdate.online :stream_socket_client(): php_network_getaddresses: getaddrinfo failed: Name or service not known (code: 0)

Apply changes to the configuration to send a test email.

Steps I have tried to fix the problem:

Opened the ports in the Firewall.
Used SSL, TLS and None connection types.
Used ports 465 and 2587.

Thank you very much for the help!