ConvertKit (now Kit) is an email-first platform that automates email marketing, newsletter growth, and digital product sales for creators.
Free·from $33/mo
About Email on Acid
What is Email on Acid?
Email on Acid is a pre-send email testing and QA platform that helps teams ensure their emails render correctly across 100+ email clients and devices before hitting send. Now evolved as Mailgun Inspect, it combines email previews, content checks, and spam analysis into one workflow.
Who is it for?
Designed for email marketers, QA specialists, and agencies who need to avoid broken layouts, broken links, or spam triggers. Ideal for teams sending high-volume campaigns or transactional emails. Not for basic email senders who don't require detailed testing.
Real use cases
Test HTML emails against the latest clients, run accessibility checks (WCAG 2.2), validate links and images, and check spam content across major ISPs with B2B/B2C segmentation. Reduce QA time and human error.
Key features
- Email Previews — See how your email renders across 100+ clients and devices in seconds.
- Spam Content Analysis — Identify red flags that could land your email in the spam folder.
- Accessibility Checks — Test against WCAG 2.2 to meet compliance like the EAA.
- Link & Image Validation — Every clickable and visual element checked for correctness.
- HTML Code Analysis — Catch coding issues that break email design.
- API Access — Integrate QA checks into your existing email pipeline.
SaaSpartout Score
7.4
/10
Editorial score from our review methodology — not user ratings.
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Email on Acid Pricing
Email on Acid pricing: from $99/mo.
For comparison: the median starting price in Marketing & SEO is $29/month, measured across 697 tools we track. See the full SaaS Pricing Index →
Basic (Mailgun Inspect)
$99/mo — Unlimited users, 1,000 email previews per month, 100+ clients, API access. Overages: $0.15/preview. Free trial available.
Premium (Mailgun Inspect)
$199/mo — Unlimited users, 2,000 previews per month, 100+ clients, API access, accessibility tests, HTML code analysis, link and image validation, spam content checks. Overages: $0.15/preview. Free trial available.
Contract (Mailgun Inspect)
Custom pricing — Unlimited users, custom previews, all Premium features, plus phone and chat support. Contact for details.
Frequently asked questions
How much does Email on Acid cost?
Email on Acid (now Mailgun Inspect) starts at $99/month for the Basic plan, with Premium at $199/month and custom contract pricing.
Is Email on Acid free?
No, but it offers a free trial. You can test the platform before committing to a paid plan.
Who is Email on Acid best for?
Email marketers, QA teams, and agencies that need to ensure flawless email rendering across many clients and devices before sending.
What are the top Email on Acid alternatives?
Popular alternatives include Litmus, EmailPreview, and Mailtrap. Compare based on your testing needs and budget.
What is the key limitation of Email on Acid?
The Basic plan includes only 1,000 previews per month; overages cost $0.15 each. For high-volume teams, consider Premium or custom plans.
Does Email on Acid include spam testing?
Yes, Premium and Contract plans include content spam analysis across major ISPs, but Basic does not.
