Hello,
we have the same issue. Our Spam Filter detects the email as sent from a spoofed sender, since it sets the header to the applicants email, but uses the admin email configured in WordPress to send.
From looking at the source code, this is hardcoded — specifically, line 178 in class-job-notifications.php:
$from_email = apply_filters(‘job-postings/from_email’, $contact_email, $job_id);
I have not found an option to change / disable this. Is it possible to create feature requests for WordPress plugins?