With Mail Merge It, you can send campaigns to not just customers, but also to your own employees. You can share an announcement, or any information that is relevant to them. You can also personalize your emails and invite them to take action (like completing a survey, or updating their tax information).
The process isn't very different from how you'd send out a regular Mail Merge It campaign. First, you'll need a list of employees you are going to be sending the campaign to. If you already have them in a sheet, great. If not, you can export the emails out of your HRMS and import it into Google Drive by going to New > File upload.
Meanwhile, create a draft in Gmail with the email you'd like to send across. Make sure you personalize the email by using placeholders to specify the name of the employee or even their team or department's name. You sure will get better clickthrough rates when you do that :)
Here's a sample email with placeholders added:
Once you're all set with the content, you can go to Addons > Mail Merge It to begin the process of sending out the campaign. You can copy paste rich HTML content into your Gmail if you want to send something that's less boring than a plaintext email. You can even attach a file (like a poster) that would get sent to everyone in the sheet.