Why is this application unofficial?
Evolution in GNOME 2.20 already includes such feature (of which I wasn't aware when I wrote my own application)
What is
this Unofficial Evolution import/export utility?:
"Evolbck" is an application for GNU/Linux written in Python and PyGTK which will enable you to import and export (in tar.gz format) your mail and settings (mail accounts, contacts, calendar, etc.) in Evolution.
Screenshots

You can send me an email, at least until the project page on Launchpad.net is ready. me an email
WARNING: this
application is only an alpha and you should use it at your own riskUNSTABLE RELEASE (0.1-0ubuntu2, released on October 01 2007)
(See my Blog for an explanation of Evolbck's features)
Licence: GPL
Package for Debian and Ubuntu
evolbck_0.1-0ubuntu2_all.deb
Source code
(only developers or users of non-Debian based distributions might want to download this)
evolbck_0.1-0ubuntu2.dsc
evolbck_0.1-0ubuntu2.tar.gz
evolbck_0.1-0ubuntu2_i386.changes
NOTE: Make sure you
have all the repositories enabled (also universe and multiverse) in
your /etc/apt/sources.list on Ubuntu
If you do not know how to enable those repositories, please take a look at this page:
enabling_extra_repositories