MailSlurp guide agent setup

Title: What Is a DKIM Selector? Why It Exists and How To Troubleshoot It
Description: Learn what a DKIM selector is, how mail receivers use it to find public keys, and how to rotate or troubleshoot selectors without breaking delivery.
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Markdown URL: https://www.mailslurp.com/guides/what-is-a-dkim-selector.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.