What's the proper way to create Group Chat feature using Ejabberd and Smack for Android?

Question

I'm using smack in my Android project. I'm trying to create a Telegram, WhatsApp like group feature. The problem is, a user can't get messages from a conference room when the user is offline. I've to rejoin the room and get history to get new messages? Is there any way, which can deliver the messages without rejoining the room.

Also trying Ejabberd mod_multicast(XEP-0033). I'm getting Packet relay is denied by service policy error.

Need help. Thanks :)

Answer 1

You can take look at MUC-SUB feature of ejabberd. It is designed for the same reason. Here is more detail you can refer.