No, this is not possible. On the Email Users Settings Page (Dashboard > Settings > Email Users) there is a list of template keywords you can add to an email to include content from WordPress. The user’s name is not one of those because by design.
Email Users sends as few messages as possible by placing multiple addresses in the BCC field. Each user isn’t getting a separate email (unless you set the BCC limit to 1), they are getting a copy of an email sent to hundreds or even thousands of other users. So there isn’t a mechanism to set a unique salutation – it would require sending one unique email to each user.
