add_action('wpcf7_before_send_mail', 'dco_wpcf7_before_send_mail');
function dco_wpcf7_before_send_mail($contact_form) {
$submission = WPCF7_Submission::get_instance();
$data = & $submission->get_posted_data();
$subject = $data['your-subject'];
if ($subject == 'Директор') {
$mail = $contact_form->prop('mail');
$mail['recipient'] = 'director@domain.com';
$contact_form->set_properties(array('mail' => $mail));
}
if($subject == 'Менеджер') {
$mail = $contact_form->prop('mail');
$mail['recipient'] = 'manager@domain.com';
$contact_form->set_properties(array('mail' => $mail));
}
}