Yahoo is the absolute worst to use, unless you are running TOR or a VPN with it, as Yahoo gives a very detailed header of your location.
Believe it or not, AOL is great as they automatically mask your locale.
With Gmail and it's scans, well..... unless your writing something about things that blow up, or other red flagged topics, it's not too bad, but there are still other better options, like crypto heaven and silent circle used to be great, but last week I was listening to an interview on NPR with silent circles founder, and I think he stated they were closing it up.
