Use mail merge to send bulk email messages - Microsoft Support
To be able to send bulk email via mail merge, you must already have installed a MAPI-compatible email program such as Outlook or Gmail. The following process assumes that you already have the message you intend to send created and open in Microsoft Word.
Applies To:
Word for Microsoft 365, Word for Microsoft 365 for Mac, Word 2021, Word 2021 for Mac, Word 2019, Word 2019 for Mac, Word 2016