Well, what you say is correct but as I am using maildirs, they have new, cur, tmp subdirs. New messages are kept in MaildirName/new/ Ex: ~/Mail/lists/evolution/new/1108409253.15564_3.myfc3 When the mail is marked old it is moved to MaildirName/cur/ as Ex: ~/Mail/lists/evolution/new/1108409253.15564_3.myfc3:2, When it is read, it's name is changed as Ex: ~/Mail/lists/evolution/new/1108409253.15564_3.myfc3:2,S What evo is doing here is that it is marking the mail old when it loads the maildirs but keeping info in index files whether the mail has actually been read or not. It works for evolution but breaks the other mail clients which exclusively depend on maildir format mailboxes protocol.
Evolution only uses the seen flag for this purpose. The use of the 's' flag is entirely to maildir spec as far as i can tell.
New mail is only new until the application has run and processed them, it is for filtering/processing, and as i understand it, shouldn't be exposed to the user directly.
