MarkAsRead
status_t MarkAsRead(int32 account, const entry_ref& ref,
BMailDaemon().MarkAsRead(account, ref, B_SEEN);
BMailDaemon().MarkAsRead(account, ref, read);
BMailDaemon().MarkAsRead(account, *message, flag);
InboundMessenger(protocol).MarkAsRead(ref, read);