Email on Acid

Email on Acid has long been a go-to tool for email marketers and developers who need to verify how their campaigns will look and perform before hitting send. Now evolving into **Mailgun Inspect**, the platform offers a next-generation email QA suite that goes beyond simple previews. It provides end-to-end content checks, spam analysis, and accessibility testing, all built on the reliable Mailgun infrastructure. For teams that prioritize flawless email rendering and high deliverability, this tool remains a strong contender in the email testing space.

Key Capabilities

The platform's core strength lies in its **unlimited email previews across 100+ clients and devices**, including dark mode rendering. This ensures that every subscriber sees the intended design, regardless of their email client. Beyond visual checks, the Campaign Precheck feature validates links, optimizes images, and tests against WCAG 2.2 accessibility guidelines -- a critical capability as regulations like the European Accessibility Act take effect. The spam testing module analyzes content against major ISP filters, helping senders avoid the spam folder before reputation is damaged.

Email on Acid also includes a built-in email editor for quick edits and real-time previews, plus advanced analytics that track opens, geolocation, and device usage. The deep-scraped content from the company's site reveals that Mailgun Inspect now offers preview results in under 10 seconds, 99.9% platform uptime, and SOC 2 Type 1 compliance, ISO 27001/27701 certification, and GDPR compliance -- making it suitable for enterprise use.

Pricing and Value

Email on Acid offers three tiers. The Basics plan at $73/month covers unlimited previews and the editor, suitable for small teams or occasional testers. The Premium plan at $112/month adds full content checking, deliverability tools, and 250,000 opens per month for analytics -- a solid step up for growing email programs. The Professional plan at $424/month includes advanced permissions and 1.5 million opens per month, designed for larger teams with high-volume sending. While the pricing is higher than some standalone preview tools, the breadth of features -- especially the new Mailgun Inspect capabilities -- justifies the cost for teams that send frequently and need robust QA.

Who It's Best For

Email on Acid is best suited for **email marketers, developers, and QA teams** who need to ensure consistent rendering across a wide range of devices and clients. It's particularly valuable for organizations that send transactional or marketing emails at scale, where a single rendering error can damage brand perception. The platform's accessibility testing also makes it a strong choice for companies subject to compliance requirements. However, occasional senders or very small teams may find the cost hard to justify compared to simpler, free alternatives.

Concluding Assessment

Email on Acid has successfully evolved into Mailgun Inspect, combining its proven preview engine with the reliability and security of the Mailgun ecosystem. The result is a comprehensive email QA platform that covers rendering, content validation, spam analysis, and post-send analytics in one place. While the pricing may be a barrier for some, the depth of testing and enterprise-grade security make it a worthwhile investment for serious email programs. For teams that demand pixel-perfect emails and high inbox placement, Email on Acid remains a top-tier choice.