Hello,
Thanks for your Patience!
We have checked out your Website and the issue is not with Canvas's Codes but with the PHP Errors (attached an image of the errors in this reply). This is likely due to the Old Version of PHPMailer you are using on your Website, while we are guessing that your Hosting Providers have updated the PHP to a more recent versions on your Servers which is causing this issue.
To fix this issue, you will need to Update the PHPMailer and upgrade include/sendemail.php to include/form.php (which is used in the Latest Versions of Canvas). This is currently the only way as your Server's PHP Version has been upgraded which makes many Old Scripts deprecated.
Hope this Helps!
Let us know if we can help you with anything else or if you find any further issues.