Thank you, Stefano.
These settings are OK on the site.
When I send, I get this error message:
SMTP connect() failed.
2018-01-27 11:52:58 Connection: opening to :25, timeout=300, options=array (
)
2018-01-27 11:52:58 Connection: Failed to connect to server. Error number 2. "Error notice: stream_socket_client(): php_network_getaddresses: getaddrinfo failed: Name or service not known
2018-01-27 11:52:58 Connection: Failed to connect to server. Error number 2. "Error notice: stream_socket_client(): unable to connect to :25 (php_network_getaddresses: getaddrinfo failed: Name or service not known)
2018-01-27 11:52:58 SMTP ERROR: Failed to connect to server: php_network_getaddresses: getaddrinfo failed: Name or service not known (0)
2018-01-27 11:52:58 SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting