Same problem here after an upgrade to version 4.4.
Even if I enter an email address with the correct domain into the “From” field, I get the error message “This email address does not belong to the same domain as the site.”
Even if I create a new contact form, this error message shows immediately, suggesting it is a problem with the plugin rather than the user input.
It would have been helpful to add the expected domain to the error message to prevent guessing and trial-and-error work.
