PLEASE, DO A DATABASE BACKUP FIRST
Go to your database in PHPMYADMIN, at SQL tab:
Firts, subscribe all contacts with “unconfirmed” status.
UPDATE `wp_mailpoet_subscribers` SET `wp_mailpoet_subscribers`.`status` = 'subscribed' WHERE `wp_mailpoet_subscribers`.`status` = 'unconfirmed';
Later, subscribe all contacts with “unsubscribed” status:
UPDATE `wp_mailpoet_subscribers` SET `wp_mailpoet_subscribers`.`status` = 'subscribed' WHERE `wp_mailpoet_subscribers`.`status` = 'unsubscribed';
And now, we have all MailPoet contacts with “subscribed” status!