How to resolve rate-limiting error from Gmail
If you see these warnings in Front, they mean that your email channel in Front is being rate-limited by Gmail, which may result in the delayed arrival of your emails in Front.
The Gmail API has upload and download limits. If you encounter rate-limiting issues, they are most commonly caused by third-party tools that are attempting to download a Gmail account's message history, such as backup software. We strongly recommend tracking down the app that is exhausting your Gmail bandwidth and adjusting its settings, if possible, or disconnecting it from your Gmail account, in order to ensure prompt delivery of all of your messages in Front.
You should be able to find the list of third-party apps that have access to that particular email account in your Google account's security page. A Google Admin can also check the User list in the Google Admin dashboard to find details on which limits were hit (see this help article).
For more information on the specific limits affecting your Google account, see the Bandwidth Limit section here.