In fairness a lot of times its a nondefault but mailing list per user configurable option. I think it isn't perhaps on this server or software but that would be one method of satisfying most. Its not a problem on a real computer or mail client worth a grain of salt however I'm often mobile and also can't view subfolders easily from this crapberry so having a subject line but keeping it in my main inbox would also benefit my ability to keep track of mailing lists and topics. Its also the reason I can't modify the original mail text I'm replying to half the time.