Also in one of our project we don’t want this functionality becouse is potencial doungerouse (Malicius user can re-register same work email for flood system).
We resolve in this way:
wp-content\plugins\mailpoet\lib\Subscribers\SubscriberActions.php
Line: 55
PHP
if ($subscriber === false) {
// create new subscriber or update if no confirmation is required
$subscriber = Subscriber::createOrUpdate($subscriber_data);
if ($subscriber->getErrors() !== false) {
$subscriber = Source::setSource($subscriber, Source::FORM);
$subscriber->save();
return $subscriber;
}
$subscriber = Subscriber::findOne($subscriber->id);
} else {
// store subscriber data to be updated after confirmation
//$subscriber->setUnconfirmedData($subscriber_data);
//$subscriber->setExpr('updated_at', 'NOW()');
$subscriber->setError(__('Indirizzo email già presente nel sistema.', 'mailpoet'));
return $subscriber;
}
In setError said in your language (email already in DB).
