Unfortunately, at MailBlue, we cannot cancel a MailBlue account prematurely to reactivate it at a later time.
If you find yourself using your MailBlue account less frequently in the near future, you can choose to downgrade your subscription to a lower tier. This way, you can ensure that all data in your MailBlue account is preserved. You can read more about how to downgrade here.
If you still prefer to cancel your subscription, you can find more information on cancelling the subscription in this article. All data from your account will be retained for one month, after which this data will be permanently deleted.