MailSlurp guide agent setup

Title: SMTP Relay Guide: Secure Setup, Delivery Flow, and Troubleshooting
Description: Learn what SMTP relay does, when to use it, and how to configure secure relay policies without creating open relay abuse risk.
Canonical URL: https://www.mailslurp.com/guides/smtp-relay/
Markdown URL: https://www.mailslurp.com/guides/smtp-relay.md

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