Press Alt to show the Menu Bar, then under View/Layout enable the Directory Pane, and under Tools select Export.

I opened the address book. Selected the tools menu and then the Export option. As I had not selected an address book I was presented with multiple save as dialogs.

So I guess export is still supported.

• Convert MAB/mork or SQLite based Address-Book into other format , MBOX (combined)-email files into other format.

Click on 'Address Book' to open Address Book. select an address book in the list, but not 'All Address Books' because that is not a real address book; it is a kind of search address book. Tools > Export Choose where to save Save as type: Select the prefered option. For example: Save as type: Comma separated (csv) types can be imported into Thunderbird and imported into various other address books. They can also be opened using other software like MSExcel and OpenOffice Calc.

Save as type: LDIF is a good option if the intent is create a backup that you later want ot import into Thunderbird address book.

click on 'Save'

Repeat the above for each individual address book.