An error occurred while sending the message - Prestashop

One of our clients contacted us because of an error while sending a message using the form within the Prestashop "Contact Us" page.

I'm using PrestaShop 1.7. Default theme. Default modules and so on. And I haven't installed anything yet.

When I send a message using the form within the "Contact Us" page it will show a message with a red background saying "An error occurred while sending the message".

I have tried to turn off modsecurity, change between php versions and some configs, but nothing seems to help. I would appreciate a lot some help with this, and I'm willing to pay for a solution if this problem is not related to the web hosting service.

There is a post related to the described issue on Stackflow. It is specifically associated with the Prestashop version mentioned.

In short, replacing the contactform.php with a previous version within /modules/contactform should resolve the issue.