Hi there,
You might need to install and route your mail through a plugin which setups SMTP. Your spinning wheel just tells me that the submission works, but the part where mail with the data from the form is sent, doesn't get to complete. So it just spins.
As mentioned above one solution would be to install this plugin; https://wordpress.org/plugins/wp-mail-smtp/ ..... go through the steps of setting up the SMTP. It's quite easy and safer then just pushing things through PHP for mail. Let me know who your email host is and I'll post the right info here for you.