Email Preview & Testing — Mailgun Inspect

Preview your HTML emails across 100+ email clients and catch rendering, accessibility, and spam issues — without leaving your browser. Mailgun Inspect brings professional email testing directly into your browser. When you’re building in Mailchimp, Klaviyo, Braze, or any other email platform, click the extension to instantly generate cross-client email previews — no copy-pasting HTML, no switching tabs, no separate login. WHAT YOU CAN TEST: • Email rendering across 100+ desktop, web, and mobile clients — including dark mode • Accessibility checks against WCAG 2.2 (45+ checks) — required for EAA compliance • HTML and CSS code analysis across 38+ issue types • Link validation — catch broken URLs before they reach subscribers • Image validation — detect missing alt text and broken image sources • Spam filter testing — B2B and B2C analysis from neutral IPs REQUIREMENTS: A Mailgun account with Inspect access (Basic from $99/month — 30-day free trial available). API key stored only in session storage. No background activity. No third-party data sharing. START TESTING: Install → open your email platform → click Mailgun Inspect → preview in seconds. DATA HANDLING • The only data the extension extracts from your browser is the HTML content of the email you have explicitly chosen to send to Mailgun Inspect when you click "Run Preview". • That HTML is sent directly from your browser to Mailgun's API (US or EU region, your choice) using your Mailgun API key. It is not sent to any third-party analytics, ad, or tracking service. • Your API key is held in the browser's session storage only. It is cleared when the browser closes. The extension does not persist your API key to disk. • The extension does not run in the background, does not read pages until you ask it to, does not collect browsing history, does not collect form inputs from unrelated pages, and does not transmit data to anyone other than Mailgun. • See Mailgun's Privacy Policy and the extension's privacy disclosures (linked in the listing) for the full picture. RESPONSIBILITY AS A USER You are responsible for the content you submit to Mailgun Inspect and for having the rights and permissions to extract and submit that content. Do not use this extension to extract or submit content you do not have the right to use. SUPPORT Use of Mailgun Inspect is governed by your existing Mailgun Terms of Service, Acceptable Use Policy, Privacy Policy, and (where applicable) Data Processing Addendum. For support, contact Mailgun support through your Mailgun account. The Chrome Web Store listing is monitored by the Mailgun Inspect product team for bug reports and questions about the extension itself.