The expiration of the unlimited email coincides with the expiration of the domain to which they are linked. The renewal order can be made either together with the domain renewal, or separately through the renewal area of the web site
If a domain is renewed, while the unlimited emails are not, after 10 days from the expiration date only the 5 standard accounts will be kept active, while the exceeding ones will be at first locked and then after another 5 days they will be finally cancelled.
If before the expiration of the last 5 days, you will not have made the cancellation of the unwanted emails, the exceeding accounts will be cancelled at random.