Normal user can add maximum 3 recipients for one message. For premium user, there is no limit on the number of recipients. But please notice that you should avoid adding many recipients for one message, split it into some messages instead.
☀ Best practice: Suppose that you want to send a message to 90 recipients, It is better if you create 3 messages separately, each one with 30 recipients and schedule them with a little bit different time.
