Or an alternative title could be “sending contacts from your address book to someone via email using Thunderbird”. This was one feature I was missing from my Outlook days and it pained me because my darn phone can do it, but not Thunderbird! I’d tried searching for this feature before and I did it again yesterday. Amazingly enough I found a forum post linking to the tool. Suspicious at first, I checked out the site and read what the author of the extension had to say. He complained that with Mozilla’s aggressive release cycle, he had to keep juggling to update his extensions and that was a waste of time. So, he uses the xpi format and makes it available on his site.
Downloading the tool was easy enough and from Thunderbird, I chose the option of installing an extension from installation files, pointed it towards the tool and I found Thunderbird informing me that it needed to restart in order to activate the tool. Super easy eh? Well, in case you run into trouble, our friend has a page with installation instructions. You may email him in case it fails to install after that.