Review for EMail Address Crawler by oHessling
Rated 4 out of 5 stars
I have installed version 5 from https://nic-nac-project.org/~kaosmos/index-en.html#eac.
I works fine with Thunderbird v10.
However, when my contacts already exist in another address book, EMail Address Crawler does not duplicate them in the targeted address book :(
To create your own collections, you must have a Mozilla Add-ons account.