The biggest problem is that E-mail demography tends to be broader than many of the other services.<p>Some of E-mail users are very conservative and specific about how they handle their E-mail. (Some of which are very risky behavior, which I actually tried to correct by explaining why that&#x27;s bad idea, but ultmately given up...)<p>There are demography between novice and expert. Novices tend to not care about changes so much; some even won&#x27;t notice changes, as long as features are somehow accessible. Experts may have some particular tastes, but they&#x27;d be quick to find solutions to change things around when they have to. But people in between tend to be very vocal about any changes and they can&#x27;t (or not willing) to find and accept &quot;solutions&quot; -- they will be the first one to complain when UI elements like buttons shift around the screen. Unfortunately, as universal E-mail gets, a lot of E-mail users fall under category. (Though, in different ways, &quot;experts&quot; can be very particular about how they handle things can be very stubborn when there&#x27;s no good reason presented to change -- but it&#x27;s a bit different context.)<p>I can&#x27;t even imagine how tough it will be to migrate some of people I know to anything other than what they are used to.