Cyrus News Daemon as poor man's replication engine

[Michael Fair]

My apologies in advance for not being subscribed to the list but I had a
quick inquiry.

I've read in the docs that the Cyrus NNTP daemon can export shared folders
via NNTP and receive an NNTP feed.  Can the same be done for user mailboxes?

I've always wondered if a group of Cyrus Servers could use their NNTP
daemons to provide fairly robust asynchronous replication for user
mailboxes.  A poor man's replication engine if you will.  Aside from the
geographic redundancy this could provide, it would be handy for users who
travel among many branch offices so their email access is to the "local"
server rather than across the WAN link. 

I envisioned that the only allowed "subscribers" to these "groups" would be
the servers themselves to feed each other changes in the user's folders.

Could this be done?
Would there be many technical challenges to use NNTP as a poor man's
replication tool?
Is there a technical reason that the NNTP engine is limited to shared
folders?

TIA,
-- Michael --