Hello @Mike Beveridge,
Thank you for reaching out to the Docusign Community.
We send a Failed Delivery notification to the Sender when TLS Enforcement is enabled it is the same "Bounceback" email template that the system uses for any other failed email delivery scenario. The system will also flag the envelope as Failed Delivery in the same way that the system does with any other email delivery failure. Currently, we don't have any in-product reports relating to email delivery failure rates/statistics. However, any feedback that can improve our users’ experience is always welcome. We invite you to share your product suggestions and feature requests on our dedicated ideas page (https://community.docusign.com/ideas), where we can collaborate to shape the future of our product together.
Note: Some advanced features and options are supported only in specific Docusign plans. Your account plan might not support some of the options discussed in this help topic. Contact your account administrator for more information about which options are available for your account. Or, visit our Plans and Pricing web page for more details on the features included with your plan. Compare eSignature plans & pricing.
Let us know if you need further assistance.
Best regards,
Christopher | Docusign Community Moderator
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