We have built for users on GSuite a plugin to interface with Inboxbooster.

SETUP

Google Workspace

1. Create an Inboxbooster free account, then click upgrade (on the navigation bar)
2. Log as as a Google Workspace administrator of your domain and go here
3. Click on Add New with the values:

Client id:103530810975734677130

OAuth Scopes:
https://www.googleapis.com/auth/gmail.labels,https://www.googleapis.com/auth/gmail.compose,https://www.googleapis.com/auth/gmail.send,https://www.googleapis.com/auth/gmail.readonly,https://www.googleapis.com/auth/gmail.settings.basic,https://www.googleapis.com/auth/admin.directory.user.readonly,https://www.googleapis.com/auth/gmail.modify