We have recently got an email from Amazon.

```
Hello,

Amazon Web Services currently supports Amazon SES API requests that are signed using Signature 
Version 3 and Signature Version 4 processes. Signature Version 4 further enhances the security around 
authentication and authorization of Amazon SES customers by using a signing key instead of your 
secret access key. To improve the security for our customers, beginning October 1, 2020, Amazon 
Signature Version 3 will be turned off (deprecated) in Amazon SES in favor of Signature Version 4.

Amazon SES customers who are still using Signature Version 3 must migrate to Signature Version 4 by 
September 30, 2020. After that, Amazon SES will only accept requests that are signed using Signature 
Version 4. For more information, see Signature Version 4 signing process [1].

What Happens if I Don't Make Updates?

Requests signed with Signature Version 3 that are made after September 30, 2020 will fail to 
authenticate with Amazon SES. Requesters will see errors stating that the request must be signed with 
Signature Version 4.

References:
[1] https://docs.aws.amazon.com/general/latest/gr/signature-version-4.html

Sincerely,
Amazon Web Services

Amazon Web Services, Inc. is a subsidiary of Amazon.com, Inc. Amazon.com is a registered trademark of 
Amazon.com, Inc. This message was produced and distributed by Amazon Web Services Inc., 410 Terry 
Ave. North, Seattle, WA 98109-5210

```

We have several PHP Codeigniter applications where we use Amazon SES SMTP credentials to send email. we don't use AWS Access Key & Secret Key to send email. So I assume this migration to Signature Version 4 wont affect on our application. Can anyone assure me that if my assumption is correct ?