[RFC] Push via e-mail?

[Alexander Belchenko]

I need to organize cooperative work with my co-worker. Unfortunately he
  cannot use bzr itself for push and pull changes. We may use only e-mail.
I'd like to know is there possible to create plugin for pushing changes
from one to other (assume that branches not diverged) via e-mail?

I suppose this plugin should prepare archive (zip or tar.gz) with all
needed info for pushing: new items from revision-store, new and updates
items from weave-store and probably new inventory.weave? And when such
archive will be received via e-mail on another end plugin should
implement pull operation based on this data.

Any hints how to implement this behaviour?

--
Alexander