Sender email address does not belong to the site domain.

Where can we see the website in question?

@takayukister

tregumakinave.al

Thought I already put the website with the question. My mistake. 

Where on the site do you have the form having the issue?

here. https://ibb.co/cyVZGw1

See How to resolve configuration errors

Hi 

Sorry, but I looked at the options and still can’t solve it. The website is using gmail, so is the smtp. I even looked at the phpmyadmin if i had any other email than the given one. The settings of smtp and gmail is good also. 

I am truly lost.?

You can turn it off with this in functions.php:

add_filter( 'wpcf7_validate_configuration', '__return_false' );

There really isn’t a valid reason to make having the site domain and email domain be the same in all cases. There are too many situations where this will never match and having no way to skip that validation is annoying but you can live with it or work around it.