Personal/Group messaging schema

Question

How to create message conversation schema in MySQL both personal group messaging. Is there a possibility to create with following scenario.

1. read/unread
2. If user delete conversation does not affect other.(For example user A & B has message conversation A clears Message then B messages should not affect)

Answer 1

How about this:

MessageGroup (
    ID, 
    GroupName
)

Message (
    ID, 
    Text, 
    MessageGroupId (FK TO MessageGroup(ID))
)

User (
    ID, 
    UserName
)

UserMessage (
    ID, 
    MessageID (FK to Message(ID)), 
    UserID (FK to User(ID), 
    Cleared (true/false)
)

This way, each user can clear the message but only for him, while others can still have their messages unaffected.