The global GLS vector in Packetracer non work with national shipping in Italy, maybe is need to intregrate with the www.gls-italy.com site.
The link to test shipping is this one:
http://www.gls-italy.com/verifica_consegna_anonimo.asp
This is a National Shipping (=Spedizione nazionale) code:
Mobabel

Thank you Andrea!
I will add this in v2.01, coming soon!