I'm very, very sympathetic to this issue, and agree that it hurts when any site goes down. However, Simple Desks was mostly a curated gallery of what already exists on the internet. A quick Google search for "Simple Desks" will turn up basically the same thing.
The other question to ask is whether permanence is a value worth holding for all things. Is it really worth holding onto all of that email? (This is a personal question, for everyone to answer, not for one person to dictate over others.)
My friend wrote a great piece on this recently (http://patrickrhone.com/2011/12/20/permanently-impermanent). It reflects on the freedom of not worrying about losing everything. He doesn't advocate being complacent, but simply acknowledging that no system is 100% sure to maintain our bits.