Messaging system – deleting a conversation

I am building a messaging system on my website. This is a threaded messaging system where a conversation can take place between two people. One of the challenges I'm working on is how to handle deleting a conversation. I am thinking of doing this similarly to how SMS conversations work on mobile phones:

• User A deletes a conversation.
• The conversation is only deleted from User A's inbox.
• User B can still view and reply to the conversation. He/she will not know that User A has deleted the conversation on their end.
• If User B sends a reply, the conversation will re-appear in User A's inbox - however the previous conversation history is not visible to them.

Do you think this is a good way to go about it? Or should a conversation disappear from both inboxes once it is deleted by either user?

One of the reasons I don't want to go down that route is if in case User A sends an abusive message and then deletes the conversation before User B has an opportunity to report it.