Mergery is a free mail merge service that allows you to send personalized emails. It is a Google Sheets™ add-on that allows you to merge data from a Google Sheet™ into a Gmail™ draft or a Google Doc™. Each row of merge data in the Google Sheet™ results in an email (from a Gmail™ draft) or a PDF (from a Google Doc™) that is customized with the data from that row of the spreadsheet.

In the template document (Gmail™ draft, Google Doc™), specify (e.g. {{first name}}) where you want the merge data placed.

Depending on the tags that you set, you can generate emails (from a Gmail™ draft template), generate PDFs (from a Google Doc™ template), or create labels. You can also generate emails with attached PDFs.

Mergery's focus is on simplicity and ease of use. It can easily work with spreadsheets that have hundreds of rows. If you have thousands of rows, this is not the tool for you - it will work, but you will need to process the rows in batches.