Rated 5 out of 5 stars

Works fine on last thunderbird version !
Sorry I didn't check correctly.
MUST select the address book first
Has a progress status bar
If more then 2 duplicates (4 or five of the same) must launch again...
The only duplicate addresse plugin on thunderbird.

Rated 3 out of 5 stars

Wish it could work !
Dont feel like ising CSV files...