MailSlurp guide agent setup

Title: HTML email code that works in Outlook, Gmail and Apple Mail: six patterns tested on 12 apps
Description: Six HTML email patterns tested on 12 email apps: a bulletproof button, stacking columns, a VML background, a fluid image, a rounded card and lists.
Canonical URL: https://www.mailslurp.com/guides/email-client-support/code-patterns/
Markdown URL: https://www.mailslurp.com/guides/email-client-support/code-patterns.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.