Eu recomendaria o complemento de Contatos do Google para o Thunderbird
Accessbi-directionalytoGooglecontactsviaaddressbooks.Thisextensiondetectsgmailaccountswhichhavealreadysetupandcreatesaddressbooksforeachofthem.CardsintheaddressbooksaresynchronizedwithGooglecontacts;theyrepresentthecurrentGooglecontactscontentsandGooglecontactswillbemodifiedwhenyoumodifythecards.TB'smailinglistsandGoogle'scontactsgroupsaresynchronizedinthesamemanner.
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