Simplify the process of producing visually rich mail merges using Gmail and combining it with data from Google Sheets. With this solution you can automatically populate an email template created as a Gmail draft with data from Google Sheets. Merged emails are sent from your Gmail account allowing you to respond to recipient replies.
Source: Repost: Sending bulk email (mail merge) using Gmail and Google Sheets – MASHe
Member of Google Developers Experts Program for Google Workspace (Google Apps Script) and interested in supporting Google Workspace Devs.