Review for Mail Merge by Alan Sillitoe
Rated 5 out of 5 stars
It took me about half an hour to figure this out, but it is actually very easy to use with an address book. I just create an email with multiple email addresses as usual and then run Mail Merge and it generates a personalized email for each recipient.
This review is for a previous version of the add-on (4.11.0).To create your own collections, you must have a Mozilla Add-ons account.