Ok risolto grazie a tutti!

Posto un how to in modo da poter aiutare altri:
URL dello script: http://batleth.sapienti-sat.org/projects/mb2md/

wget http://batleth.sapienti-sat.org/proj...2md-3.20.pl.gz
gunzip mb2md-3.10.pl.gz

usage:
mb2ms -s /var/spool/mail/username -d /home/username/Maildir

esempio:
perl mb2md-3.20.pl -s /var/spool/vbox/miodominio.com/username -R -d /home/vpopmail/domains/miodominio.com/username/Maildir/


E' necessario avere installato il TimeDate perl library

ecco come installarlo:
wget http://search.cpan.org/CPAN/authors/...te-1.16.tar.gz
gzip -dc yourmodule.tar.gz | tar -xof -
perl Makefile.PL
make
make test