Moving from local storage to imap: advice wanted

[Rasmus Villemoes]

Hi there

I started using emacs/gnus on my university account around 10 years
ago. So far, all mail has been pulled from the server and stored
locally in what I think is Maildir format (each group in Gnus has an
associated folder under ~/Mail, with one mail per file). Outgoing mail
and news has been stored in (mbox?) files
"sent-(mail/news)-yyyy-mm". I have been relying on the university's
backup of user files in order not to lose mail.

But I may not keep that account for ever, and running emacs via an X11
connection from the other side of the Atlantic is not very
practical. So I want to find another solution. Naturally, I still want
to be able to access all my old mail and sent mail/news, which totals
around 2GB. I suppose I could more or less just copy the ~/Mail
directory and ~/.gnus from my university account to my laptop and keep
doing things the same way, but my laptop is too likely to crash or get
stolen. So I'm looking for a hosting solution offering:

(a) imap access, of course
(b) automatic backup
(c) a way to upload all my old messages
(d) at least 10GB storage

It's not hard to find places offering (a) and (d). (b) is not that
advertised, but I suppose that it's implicit when offering any kind of
storage. Also, I think offlineimap may be used to dump snapshots
periodically. What I'd like to know is if anyone has experience with
(c). 

Somewhat related: Assuming I find such a place, I of course need to
change my Gnus configuration. There are lots of tutorials on how to
fetch mail from an imap server. But how do I manage to keep track of
outgoing messages? Is the best way simply to Bcc all mail and news to
oneself, and then use the From-address to filter it into appropriate
folders? It feels kind of backwards.

-- 
Rasmus Villemoes
<http://rasmusvillemoes.dk/>