I think email is the ultimate form of bad skeumorphism. It was designed to mimic postal mail. Email addresses, no permissions, no true id checks, no punishment for abuse. Many of the now used features like spam folders, filters, encryption, receipts were just tacked on (poorly). And because it's a "worldwide standard" that no one controls it's impossible for someone with a vision to try and change email.
I say abandon "fixing email" and come up with a new solution altogether. Start with a clean slate. Form a coop or nonprofit foundation that will control the standard for 5-10 years until everything's ironed out, then release the source code so people and providers can use it to replace email and people don't have to depend on one group of people. At this point I'm willing to try anything, as I'm sick of email, I HATE it with every fiber of my being. Spam and delayed newsletter bombing is taking up hours of my time each week.
This is my position exactly. And skeumorphism wasn't even in my vocabulary (until now, thanks!). The example I tend to compare email to is the general design of early electric lights: so many of them simply looked like gas lamps into which an electric bulb had been jammed. Like these: http://goo.gl/808F6 Sure they're pretty, but over time, we've designed much better electric lights by moving away from the restrictions imposed by an open flame. Email, on the other hand, hasn't evolved much at all since its birth in 1982 (!), and better filters simply don't impress me anymore.
And the cost in bandwidth and wasted time email and its spam problem impose on us cannot be understated. We really do need something new.
Email became unwieldy when it became a universal communication mechanism. Sending email does not mimic a very important characteristic of post, sending email is free. All abuse would stop if people were required to place a paid-for 'stamp' on each email they sent. Failing that, email will only be replaced by something else that people want to use en-masse, facebook messaging probably.
The idea that you could come up with an alternative messaging solution is beyond silly. Why would people use it? Any migration would require both systems to run in parallel but unless the new system incorporated every feature of the current email infrastructure people would simply not bother. And if it incorporated every feature then the abuse would migrate over too.
Better skeumorphism of mail? Sure, like refactor and split mail from postage parts completely? Chris, can we connect with you over email? (the irony, ha!)
[Disclosure: I work for the project linked above.]
I say abandon "fixing email" and come up with a new solution altogether. Start with a clean slate. Form a coop or nonprofit foundation that will control the standard for 5-10 years until everything's ironed out, then release the source code so people and providers can use it to replace email and people don't have to depend on one group of people. At this point I'm willing to try anything, as I'm sick of email, I HATE it with every fiber of my being. Spam and delayed newsletter bombing is taking up hours of my time each week.