Database design for email messaging system

Question

I want to make an email messaging system like gmail have. I would like to have following option: Starred, Trash, Spam, Draft, Read, Unread. Right now I have the below following

Answer 1

If I were you I would set two flags one for sender and other one for receiver if both flags are true then message should be deleted from database otherwise keep that in database but hide it from who deleted it.

Do same thing for trash. You may want to run cron or check manually if both sender and receiver delete the message then remove it from database.