Best Email Testing · head-to-head
Mailtrap vs Mailgun Inspect (formerly Email on Acid)
A sourced, side-by-side comparison for email testing. Mailtrap has the lower entry price. Every figure links to the vendor's own page and the date we captured it.
At a glance
- Price: Mailtrap $0/mo vs Mailgun Inspect (formerly Email on Acid) $99/mo — Mailtrap is cheaper to start.
- Free tier: Mailtrap Yes; Mailgun Inspect (formerly Email on Acid) No.
- HIPAA: Mailtrap —; Mailgun Inspect (formerly Email on Acid) Yes.
Side by side
| Mailtrap | Mailgun Inspect (formerly Email on Acid) | |
|---|---|---|
| Entry price | $0/mo (Free) | $99/mo (Basic) |
| Free tier | Yes | No |
| HIPAA (BAA) | — | Yes |
| SOC 2 | Yes | Yes |
| GDPR | Yes | Yes |
| Best for | Developer teams | Teams already on Mailgun |
Sources — Mailtrap: mailtrap.io (verified 2026-06-18). Mailgun Inspect (formerly Email on Acid): mailgun.com (verified 2026-06-18).
Key features
Mailtrap: Fake SMTP server that traps emails (never sends to real recipients); HTML/CSS compatibility checker and spam score (SpamAssassin); Multiple isolated sandbox environments per team; API and SMTP access for CI/CD integration
Mailgun Inspect (formerly Email on Acid): 100+ email client and device previews; Accessibility testing and HTML code analysis; Link and image validation; Spam content checks on Premium+