Gmail API error 429 - how to resolve the error? - google-api

Question

This is the error I am getting from Gmail, and I am wondering how to resolve this. It appears I have reached a quota.
Mailer: Gmail
{
"error": {
"code": 429,
"message": "User-rate limit exceeded. Retry after 2021-02-15T06:43:03.309Z
(Mail sending)",
"errors": [
{
"message": "User-rate limit exceeded. Retry after 2021-02-15T06:43:03.309Z (Mail sending)",
"domain": "global",
"reason": "rateLimitExceeded"
}
],
"status": "RESOURCE_EXHAUSTED"
}
}

Answer 1

There are two types of quotas, project based quotas which are applied to your full project and user based quotas which are applied to the authenticated user who is making the request.
User rate quotas are flood protection they ensure that a single user does not make to many requests at one time
User-rate limit exceeded. Retry after 2021-02-15T06:43:03.309Z
(Mail sending)",
The error message you are getting now tells you that you have exceeded the send mail quota and you can make a request again after 2021-02-15T06:43:03.309Z .
Solution wait until after 2021-02-15T06:43:03.309Z to make another request, and when you start making requests make sure to slow down so you don't make to many requests and exceed your quota again. A specific technique to retry requests and wait is the exponential backoff where you try a request and wait exponentially increasing periods of time if it fails to give the server time enough for not overpassing the rate limit.
Reference
Resolve 429 error in Gmail API
Retry failed requests
Exponential backoff