Mozilla Thunderbird address book allows you to create lists that you can use to send e-mails to a group of persons. The same functionality is supported in Convergence in the form of groups. You can import an address book, that has groups, to Convergence in the Mozilla Thunderbird ldif format. However, lists will not be displayed after the import. You need to log out and login to Convergence to view the lists. Lists present in the address book will displayed as groups in Convergence address book.