Notifying Assigned Agents When Outbound Email via SendGrid SMTP Is Undeliverable

[BrunoPer]

Hi there!
I'm looking for help in implementing a notification workflow for our agents in the scenario where emails sent from ServiceNow (using SendGrid SMTP) do not reach their intended recipients.

Current Setup:
Outbound email in ServiceNow is configured to use a SendGrid SMTP account (connection shows as operational).
Email sending and receiving are fully functional (as verified via Email Diagnostics and Connection).
We have configured our Outbound Email Properties to handle SMTP retries as recommended.
We intend to use SendGrid's Event Webhook to receive near-real-time events such as bounce, dropped, or blocked messages.

Business Requirement:
When an email is undeliverable, we want to:
Identify the related ServiceNow record from which the email was generated.
Alert the user in the assigned_to field (e.g., via notification or work note) that the email did not reach its recipient.

Request for Assistance:
Are there any best practices or pre-delivered utilities/plugins in ServiceNow for handling this type of integration?
Is matching the SendGrid message ID with the ServiceNow sys_email table reliable, or are there edge cases/supportability concerns we should be aware of?
Are there any recommended approaches for handling security for the Scripted REST API that could handle SendGrid webhooks?

Reference Details:
SendGrid SMTP account is successfully connected.
Email sending and receiving in ServiceNow are operational.

Guidance and any examples or recommendations that will help us create a proactive notification process for our agents.


Thank you!

#sendgrid