I decided to release the source code of an old project of mine. It’s a simple Java app that handles batch/scripted emails to large numbers of recipients using your gmail/yahoo/etc. account.
The idea is you load/fill in a table where each row is a recipient and each column is a piece of corresponding data about that recipient. Then you can write a template email that gets sent to each recipient, pulling the relevant data from each row of the table.
Source as zip