Forms not sending anymore, unclear what the backend error is.

Question

The answer in the related forum post was "you are using form widget with CAPTCHA". However, I am not using the CAPTCHA.  My widget string is only {$form:contact:Send}, and it doesn't display the captcha box. So it should not need the captcha during validation of the submitted form.
All forms worked until recently and suddenly stopped working, even in new Toaster installations on the same hosting. I assume something was done on the hosting, but it's hard to tell what without having more hints from SeoToaster about the cause of the error. Is there a way to find out why exactly the form post fails?

Thank you,

Philippe

Answer 1

Web hosting provider deactivated @mail function on the server, which caused this to happen. I'm going to use SMPT instead.
This can be closed.