Eh, it's just something that annoys me. "Date sent" is all my webmail client has too, and it's good enough to use for a day or two, but I miss at least one new mail a day due to it not showing up near the top of the list, and I have to use my regular IMAP client to catch it. (I keep so many marked-as-unread mails that the unread counter isn't useful to avoid that problem.) Also, it's terrible for archiving, which I do a lot of.

And I don't consider "tell your friends to [anything]" a viable workaround for a bug. My client should be able to handle their mistakes (or, in some cases, deliberately wrong computer clocks).