MailSlurp guide agent setup Title: Email Spam Testing Guide for Pre-Send Validation Description: Run email spam testing before launch to reduce inbox placement failures and improve deliverability with auth, header, and content checks. Canonical URL: https://www.mailslurp.com/guides/send-spam-test-emails/ Markdown URL: https://www.mailslurp.com/guides/send-spam-test-emails.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.