spf issues with SES - get a bounce sending email

Hello.

Did you configure Easy DKIM when performing domain authentication?
https://docs.aws.amazon.com/ses/latest/dg/send-email-authentication-dkim-easy.html

The SPF record should be set to "amazonses.com" by default, so I think it will pass checkers.
However, if you want to set MAIL FROM with your custom domain, you will need to set up an SPF record.
https://docs.aws.amazon.com/ses/latest/dg/send-email-authentication-spf.html

Messages that you send through Amazon SES automatically use a subdomain of amazonses.com as the default MAIL FROM domain. SPF authentication successfully validates these messages because the default MAIL FROM domain matches the application that sent the email—in this case, SES. Therefore, in SES, SPF is implicitly set up for you.

However, if you don't want to use the SES default MAIL FROM domain, and would rather use a subdomain of a domain that you own, this is referred to in SES as using a custom MAIL FROM domain. To do this, it requires you to publish your own SPF record for your custom MAIL FROM domain. In addition, SES also requires you to set up an MX record so that your custom MAIL FROM domain can receive the bounce and complaint notifications that email providers send you.