only 1 mail imported in Evolution 2.30.3 ubuntu 10.10

[Horst Werner]

I saved my email-folders with "save as mbox" in Evolution ??? on ubuntu.
When imported these folders in Evolution 2.30.3 on same ubuntu on another machine, I get only one messages per folder.
Whats wrong (or can I change this behavior)
I want to import all mails.

ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: evolution 2.30.3-1ubuntu6
ProcVersionSignature: Ubuntu 2.6.35-22.33-generic 2.6.35.4
Uname: Linux 2.6.35-22-generic i686
Architecture: i386
Date: Wed Dec 5 16:22:18 2012
ExecutablePath: /usr/bin/evolution
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release i386 (20101007)
ProcEnviron:
 SHELL=/bin/bash
 LANGUAGE=en_US:de:en
 LANG=de_DE.utf8
SourcePackage: evolution
XsessionErrors:
 (polkit-gnome-authentication-agent-1:1500): GLib-CRITICAL **: g_once_init_leave: assertion `initialization_value != 0' failed
 (nautilus:1507): GConf-CRITICAL **: gconf_value_free: assertion `value != NULL' failed

[Andre Klapper (a9016009)]

Save as mbox only saves one email, see https://help.gnome.org/users/evolution/3.2/exporting-data-mail.html.en