email over webDAV as IMAP replacement?

i'm interested in associating meta-data with emails stored in a central
repository accessible from multiple clients. on day i'd like to be able
to share my mails and meta-data over the internet.

but this is brings me to IMAP. as a developer, IMAP sucks. IMAP really
sucks. IMAP *really* sucks for so many reasons.

it's a big, complex, obscure protocol. good secure server
implementations are tough to code available only in a limit number of
languages. it does too much. it's just not safely hackable.

webDAV is cool. it's a modern hackable mashable protocol. running over
http means security, scalability, caching and mirroring can be left to
httpd. this is great if i want to share my email archives and meta-data
over the internet. protocols have been successfully layered on top of it
(subversion, calDAV for example). it strikes me as a good match for an
IMAP alternative whose strength is read only performance and associating
meta-data with emails.

has it been done before? is this just a crazy idea?

tell me why it won't work!

- robert