AmazonSES Error: InvalidClientTokenId - Signature Version 3 requests are deprecated from March 1, 2021. From that date on, we are progressively rejecting such requests. To resolve the issue you must migrate to Signature Version 4. If you are self-signing your requests, refer to the documentation for Authenticating requests to the Amazon SES API [1] with Signature Version 4 [2]. If you are not self-signing your requests, simply update your SDK/CLI to the latest version. [1] https://docs.aws.amazon.com/ses/latest/DeveloperGuide/using-ses-api-authentication.html [2] https://docs.aws.amazon.com/general/latest/gr/sigv4-create-canonical-request.html