Forms not sending emails

Hi,
My client bought ERE with the Beyot theme last year. It appears that the contact form on the individual property page is not working. It hangs with the message “sending email, please wait”. Nothing happens, no email, nothing.

I have checked the SMTP settings in the WP SMTP plugin and they are correct, so something in the form is clearly not working.

Thanks in advance for your help resolving this problem.

Regards,

The page I need help with: [log in to see the link]