If your Meteotemplate web is hosted on Altervista, you need remove the whitelist restrictions:

Go on the control panel of Altervista.
Click on menù RESOURCES
Look for the PHP panel
Click on "Modify PHP settings" 
Move down the page until you find "Server to Server Connections"
Put your mobilephone number in the form and follow the procedure with the SMS
Click on the "Externa connection without restrictions"
Clikc on Save