G Suite Marketplace offers a wide range of quality enterprise apps that add functionality and features to native Google Cloud apps. Mailmeteor is a verified G Suite add-on. To use Mailmeteor you need to install it first on your domain.
Open the Mailmeteor page on the G Suite Marketplace. Make sure that you're logged in with your G Suite Admin account to the Marketplace.
Click on the "Domain Install" button as shown below.
When the consent popup appears, click on "Continue"
Then, choose the domain on which you want to install Mailmeteor.
Review permissions, tick the Terms of services box, and click on "Accept"
Mailmeteor has been installed! Click on "Done".