What is the deletion policy regarding deleted messages? Are they actually deleted and lost forever or the deletion is a logic mark but the message still exists in the quickblox db?
When you delete a message then it will be deleted only for you but stay for other users in chat.
When each user in chat deleted it then it will be completely removed.
But there is a 'force' logic - an owner of chat message (sender) can delete it completely via 'force=1' flag.