behaviorOnMxFailure

The action to take if the required MX record can't be found when you send an email. When you set this value to USE_DEFAULT_VALUE, the mail is sent using amazonses.com as the MAIL FROM domain. When you set this value to REJECT_MESSAGE, the Amazon SES API v2 returns a MailFromDomainNotVerified error, and doesn't attempt to deliver the email.

These behaviors are taken when the custom MAIL FROM domain configuration is in the Pending, Failed, and TemporaryFailure states.