Earlier quoted context omitted.
We use Zimbra at work. I'd have a hard time recommending it unless you really, really want 80% of Exchange and 40% of the usability. (Outlook Web Access is still the only webmail client I've found that is in GMail's ballpark. Since running an Exchange server is beyond my skillset, my interest, and my budget, and trusting a managed Exchange host feels odd--at that point I might as well just stick with GMail. So I do.…
"[Gmail/Facebook/USGov/etc] isn't going to find anything particularly interesting about me by my mail, anyway." There are two problems here: 1. We look at our data from our point of view. Other people and orgs have their own points of view, and it's their actions driven by their points of view that we need to worry and think about. For example, you think your mail is uninteresting, yet Google enhances the value of th…
Even if you were trying to be all sneaky about your email by having your own service set up somewhere, you're still making copies of everything you send by virtue of sending it. It's more vectors for the government/Evil Google/whoever to need to scan to get a picture of the data you're creating, but it's not impossible.
I know you're just making a point, but to the people who actually are all tinfoil hat, this whole conversation to shift to whether or not you should even use email as a method of communicating.