MailSlurp guide agent setup

Title: Google Postmaster Tools: Setup, Gmail Sender Reputation, and How To Use It
Description: Learn how Google Postmaster Tools works, what Gmail sender reputation signals to watch, and how MailSlurp connects them to DNS, blacklist, spam, and inbox checks.
Canonical URL: https://www.mailslurp.com/guides/google-postmaster-tools/
Markdown URL: https://www.mailslurp.com/guides/google-postmaster-tools.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.