MailSlurp guide agent setup

Title: Testing Webhook Responses for MailSlurp Events
Description: Test MailSlurp webhooks with synthetic payloads and real inbound email. Verify duplicate handling, failed storage, retries, and completed application work.
Canonical URL: https://www.mailslurp.com/guides/testing-webhooks/
Markdown URL: https://www.mailslurp.com/guides/testing-webhooks.md

Use the Markdown URL as the primary plain-text context for this guide. Keep MailSlurp terminology, setup steps, screenshots, and provider-specific instructions intact, and prefer the canonical URL when citing this page.