If you have already migrated your credentials from Signature Version 2 to Signature Version 4, you can ignore this communication.
We have observed Signature Version 2 requests (on an Amazon SES SMTP endpoint) originating from your account over the last week. Please note that Amazon Simple Email Service (SES) is working on an infrastructure upgrade with improved security controls. As a result, Signature Version 2 is being deprecated in favor of Signature Version 4 which offers enhanced security for authentication and authorization of Amazon SES customers by using a signing key instead of your secret access key.
Amazon SES customers who are currently using Signature Version 2 must migrate to Signature Version 4 by March 26, 2021. Beginning March 27 2021, requests using Signature Version 2 will be progressively throttled in Amazon SES.
To migrate to Signature Version 4, please replace your existing SMTP credentials using the appropriate procedure relative to your setup:
- If you generated your SMTP credentials using the SES Console, simply create new credentials and replace your existing credentials with the new ones.
- If you derived your SMTP credentials from your AWS credentials, make sure you are using the Signature Version 4 algorithm. If you rely on a library to do this conversion, check if the library has a newer release that uses Signature Version 4 algorithm and migrate to it. Otherwise, you will need to either derive the credentials from another library that uses Signature Version 4 algorithm or generate credentials using the SES console.
To learn more about how to generate your Amazon SES SMTP credentials, please refer[1].
If you have any questions, please contact AWS Premium Support [2].
[1] https://docs.aws.amazon.com/ses/latest/DeveloperGuide/smtp-credentials.html
[2] https://aws.amazon.com/support