I always have a love/hate relationship with Google products. I do not trust that they will always stay around and I do not trust that it keeps my information.
Gmail user? Go to https://mail.google.com/mail/#all/p1000000 and an error message will redirect to a page that shows the oldest messages from your account.
I did it and found messages that seemed to be hidden somewhere from Google Buzz (defunct Google service). I was glad to be able to delete all of that! I had no idea where it was holding it. The labels to sort in Google Plus always seem to baffle me and I tend to prefer my Yahoo mail which does not do funky things.