Use Google Sheets to mass send identical HTML- formatted emails (with only a change in the name addressed) for free.
Make a copy of this Google Sheets: https://docs.google.com/spreadsheets/d/1kgaWzGyjkAYkQWZjEsnVgt5XHIqxs8a6sePgvsbWShY/edit?usp=sharing
Instructions are all there!