MailSlurp guide agent setup

Title: Node Send Email SMTP Guide (Nodemailer, API Sends, and Testing)
Description: Send email with Node.js SMTP using Nodemailer, secure auth/TLS settings, HTML, attachments, API sends, and receive-side testing workflows.
Canonical URL: https://www.mailslurp.com/guides/smtp/node-send-email-smtp/
Markdown URL: https://www.mailslurp.com/guides/smtp/node-send-email-smtp.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.