Is it okay to engage with users after one-two months, if they are not officially subscribed to the clients’ Chatbot?

Is it okay to engage with users after one-two months, if they are not officially subscribed to the clients’ Chatbot?

There is an official policy from Facebook advising the best practice is to do subscription messages through one-time notificationsYou may refer to the Facebook subscription policy here as well. 

Please click here to set up one-time notifications on Stella.