To try the thousands of add-ons available here, download Mozilla Firefox, a fast, free way to surf the Web!
CloseWelcome to Firefox Add-ons.
Choose from thousands of extra features and styles to make Firefox your own.
CloseReview for Provider for CalDAV & CardDAV by Andrew Lohmann
Rated 2 out of 5 stars
Provider CARDDAV CALDAV is not so good with Yahoo yet.
This looks as if it is going to be a very good add-on once it is working well. Unfortunately, Yahoo contacts support are not fully functional yet so CardBook, TbSync and Thunderbird CARDDAV address book does not work fully yet.
The best thing to do is export all your lists then import them to your email providers contacts one list at a time. I use all three but with different email providers to see which turns out to work best.
https://engineering.andrew-lohmann.me.uk/windows-2-linux---operating-systems/linux-windows-maintenance#h.fkwlnkdyfb0o
To create your own collections, you must have a Mozilla Add-ons account.