New recipients are recorded on a waiting list after your limit is exceeded. That means, they won’t be lost, but they don’t get any messages from you. Of course, you can continue to send unlimited notifications to all active recipients generated up to the limit with your tariff.
If the recipient limit is exceeded, there is no automatic rate increase. However, we will inform you in your account in good time before you reach your limit, so that you can increase your rate at any time and reach your full potential of recipients.