Found myself writing a long post on a yahoo group about why and what I do to secure my email inbox against catastrophic loss, and thought it was worth boring to tears sharing with my blog readers. So what do you do? What's your solution or insurance policy for your email?
Note: This is going into my Tales from my Science Fiction Life file because honestly, email is something that came into being during my adulthood. When I was in college, no email. Grad school, we used IRC (Internet Relay Chat) and sometimes we found information on newsgroups. Post-grad my first work email was a ccmail  account. One of my email addresses has the number 99 in it because that's the year I created the account. So, it's been only a bit more than 10 years, really, since this stuff has mattered, and today it matters a great deal. But enough about history, back to our regularly scheduled lecture information session about email and backups.
For email, I've switched over to gmail for my primary email storage, although that is putting my eggs in *their* basket, it's a pretty reliable one (they have multiple redundancies and things like bomb-proof bunkers, I trust them, your mileage may vary.)
I use email accounts that run the IMAP protocol, which who the heck knows what it stands for, but means that the server and the email clients sync with one another. Contrasted with POP and/or POP3 (which tries to do something similar but does not.) Main point - there are copies of all messages on the server, until you manually delete them from one of your readers (sometimes there's another copy, if it was synced down from the server before you deleted it and you haven't synced back up to the server again yet, but this is temporary and somewhat rare unless you're a freak like me...)
I use Thunderbird as my email client (mozilla free download - same people that bring you Firefox browser.) I have it running on my iMac and my macbook. I also then have my iPhone hooked up to my email accounts (yes, there are multiple email accounts, and yes, there are a lot of computers/tech in my house. Geek, remember? I prioritize tech over almost every other household purchase! Some days the cats don't eat because mamma needs some new tech. Just kidding. Meow.)
When I check mail on my phone while out and about, it fetches me the latest from the server, which may mean 5 new messages, as well as 8 or 10 deletions from when I was at my desktop earlier in the day. Very convenient for checking mail from many places. I can check on a computer at the library using gmail.com via a web browser, and again those changes will be fetched down to my other computers next time I log in on them.
Can't beat the convenience, and because it's all server-side it means I can't really lose that email inbox. A local copy is stored on each of the other machines (the phone carries only the last 50, though you can dig back into your inbox deeper by fetching more messages manually) so there's a quasi-backup there, plus the server copy.
Again, all my eggs are in gmail's basket, but it's giving me the convenience of what I need. I even run one of my other email accounts through a shell gmail account because I prefer gmail's way of handling messages and I was having a spoof problem with that account. The only hitch is that the first time you download the mailbox to a new machine, at least in my case because I'm a digital packrat, it takes a while (I have 5k messages in my inbox. I delete a lot, but get a LOT!)
I predict this kind of mobile connectivity will be standard in the future, in fact I'm waiting for my invitation to download a copy of RockMelt, a new browser that's more tuned into the social web because I think they're starting to head that way - basically more awareness of the constantly moving user, one who uses multiple types of devices all day and needs access to their core "stuff" be it email, files, images, movies, music library, digital books, friends, contacts, etc. Stay tuned for ... more tales from my science fiction life!
 If you actually follow all the links from this note to the wikipedia articles, you can get a nifty little primer in Ancient Internet Tech, aka "You kids get off my lawn!" stuff. Lovely. When, exactly, did I get so old??