Import of contacts from additionally addressbooks

Open thunderbird and choose the address book you want to import.

->address book -> choose the address book -> Export (view picture)

It is necessary that you save the file as .csv

Afterwards you can import the .csv file via Zimbra webclient.

Login at https://mail.desy.de 

->Preferences ->Import/Export -> Import -> choose the .csv file-> Target = Contacts -> Import