Problem sending mail with SMTP in Contact Form

I have problem sending mail with smtp in my contact form and newsletter form, the error is:

Email could not be sent due to some Unexpected Error. Please Try Again later.
Reason: SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting

The problem is not the provider because i have many web site with this provider and i have not problem with the other.
Help thanks

Marco F.

The page with this form is

http://www.agrobotica.it/IT/contatti.html

Problem solved
thanks