The vCard format, or VCF, is a personal data format that acts as an electronic business card. A VCF file can contain names, e-mail addresses and URLs, telephone numbers, addresses and multimedia information, including photos and audio files. Mozilla Thunderbird, a free, open-source e-mail client, does not directly support VCF. However, a free Thunderbird add-on is available that allows the export and import of VCF files, as individual contacts and all address book contacts. These VCF files can be imported to other e-mail clients, such as Microsoft Outlook, or to mobile phones.
Navigate to the Kaosmos website at nic-nac-project.org/~kaosmos. Click "MoreFunctionsForAddressBook" in the left pane and download the version of the add-on appropriate for your version of Thunderbird from the bottom of the page.
Open Thunderbird. Click "Tools," then "Add-Ons." Click "Install" and double-click the MoreFunctionsForAddressBook XPI file you downloaded. Click "Install Now." Click "Restart Thunderbird" when the installation is complete.
Click "Address Book." Highlight the address book you want to export in the Address Books panel. Click "Tools" and select "MoreFunctionsForAddressBook."
Click "Actions For Address Books" and click "Export As VCF." Enter a name for the VCF file and click "Save."
You can also export your contacts as LDIF, CSV or TXT and use a third-party converter to convert these files to VCF.