How to Switch from Email on Acid, Step by Step
Leaving Email on Acid means moving three things: how your ESP sends tests in, any API calls, and how your team reviews. This guide covers each step with EmailQA as the destination, and what switching costs compared with staying on Mailgun Inspect.
For what Mailgun Inspect changes and when your account moves, see Email on Acid is becoming Mailgun Inspect. We make EmailQA, so every claim about Inspect here links to Mailgun's own pages.
The short version
- Your Email on Acid account moves to Mailgun Inspect: subscriptions from June 2026, annual plans at the end of their term, contracts at renewal.
- Test history doesn't transfer to Inspect, so export the screenshots you need first.
- Your ESP test lists need a new address either way; EmailQA gives every account, Free included, a private send-in address.
- API integrations need new endpoints and auth either way; EmailQA's API is on the $99 Business plan.
- EmailQA renders on 12 real clients with team review built in; Pro is $20 a month for 1,000 renders.
- It doesn't do accessibility or spam checks, so keep a QA suite if those are part of your sign-off.
What to check in any replacement
Seven questions settle most evaluations; ask them of every tool, including ours.
- Which clients do your subscribers use? Pull opens by client from your ESP and test those, not a vendor's whole catalog.
- How are screenshots made? Ask whether your email is delivered to real client apps on real devices or rendered in an emulator.
- How is usage counted? Check whether dark mode counts separately, and what happens at the limit: overage, a pause or a hard stop.
- Can you send in from your ESP? Look for a fixed address you add to a test list once.
- Who can review? Check whether clients and stakeholders can comment and approve without a paid seat.
- What carries forward? Ask how long screenshots are kept and whether there's an API with webhooks.
- What does your security team need? Match the vendor's certifications and SSO support to your requirements.
Where EmailQA fits
EmailQA renders your email on real devices and adds team review, from $20 a month.
- Real devices, real apps: each email is delivered over SMTP and opened in the actual client, including Word-engine Outlook on Windows and Gmail and Outlook on physical iPhones and Android phones (how it works).
- 12 clients: Outlook on Windows (classic and new), Mac and the web; Apple Mail on Mac and iPhone; Gmail on the web (Mac and Windows), iOS and Android; Outlook on iOS and Android. Light and dark mode count as one render.
- Review built in: reviewers pin comments on the email without an account and compare versions; Pro adds approvals and Slack notifications.
- ESP send-in: every account, Free included, gets a private send-in address; add it to your ESP's test list once. Each test send becomes a project, usually within a minute; setup is below.
- ESP imports: pull campaigns from Mailchimp, Klaviyo, HubSpot, ActiveCampaign, Campaign Monitor, Constant Contact, ConvertKit, AWeber and Drip, or designs from Figma.
- API: REST endpoints and signed webhooks on Business, with API renders landing in the same review UI (rendering API).
| Plan | Price | Real-device renders a month | Highlights |
|---|---|---|---|
| Free | $0 | 25 | 3 projects a month, 2 team members, 7-day history |
| Pro | $20 a month, or $200 a year | 1,000 | Unlimited projects, 10 members, approvals, Slack, 90-day history |
| Business | $99 a month | 3,000, then $0.05 each up to 12,000 | REST API and webhooks, white-label reviews, 25 members, 1-year history |
Every account starts with a 14-day Pro trial with 50 renders, no card required (pricing).
What EmailQA doesn't do: accessibility checks, spam testing, email analytics, or legacy clients such as Lotus Notes, AOL and older Outlook versions.
Stay on Inspect instead if you need 100+ clients from one tool, accessibility or spam checks are part of your sign-off, or you want previews inside your ESP's editor through Mailgun's Chrome extension. Some teams run both: Inspect for audits, EmailQA for real-device review.
What it costs at your volume
At 3,000 previews a month, Inspect lists at $349 to $399 and EmailQA costs $99.
| Previews or renders a month | Inspect Basic | Inspect Premium | EmailQA |
|---|---|---|---|
| 500 | $99 | $199 | $20 (Pro) |
| 1,000 | $99 | $199 | $20 (Pro) |
| 2,000 | $249 | $199 | $99 (Business) |
| 3,000 | $399 | $349 | $99 (Business) |
| 5,000 | $699 | $649 | $199 (Business) |
List prices as of October 8, 2026, before Mailgun's migration offer of a free first month and three months at 20% off. Above 2,000 previews a month, Mailgun suggests a contract, which it says costs less per preview; the 3,000 and 5,000 rows show list-price overage. Inspect counts each client or device tested as a preview; EmailQA counts each client as one render, light and dark together, across its 12 clients.
EmailQA Pro pauses rendering at 1,000 a month rather than billing overage. Premium's price also covers accessibility, code, link, image and spam content checks, which EmailQA doesn't offer. Over a year, Inspect Basic's plan fees are $1,188 at list price, before overage; EmailQA Pro billed yearly is $200.
How to switch from Email on Acid
Time the switch to your renewal date, and run both tools side by side for one send cycle.
- Find your date. Subscriptions move from June 2026; annual accounts move at the end of the term, contracts at renewal. If you're leaving, cancel before it renews.
- Export what you keep. Download the screenshots and results you need for clients or audits; they don't transfer to Inspect.
- List the clients you test. Compare your Email on Acid client profiles with your ESP's opens by client.
- Start a trial. EmailQA's 14-day Pro trial includes 50 renders and needs no card; run your last few campaigns through it alongside Email on Acid.
- Re-point your ESP. Swap your Email on Acid address for your EmailQA address (Settings, under "Send a test to EmailQA") in each test list, or import campaigns directly.
- Move API calls. Use the mapping below; the API is on the Business plan.
- Invite reviewers. Share preview links; reviewers comment without an account.
- Cancel Email on Acid once a full send cycle has gone through EmailQA.
Move your send-in workflow
Your ESP test lists keep working once you swap one address. EmailQA's send-in address is private to your account and included on every plan, Free too.
| Email on Acid | EmailQA |
|---|---|
| A static auto-process address per account | A private address per account, in Settings under "Send a test to EmailQA" |
A +customer_id suffix to tag a test | Plus labels such as +welcome still arrive |
| X-Headers to pick clients | Pick clients when you render the project |
| Results in your Email on Acid inbox, with an email when ready | Each send becomes a project named after its subject line, usually within a minute |
The HTML is kept exactly as your ESP sent it, so you review what it actually sends, including any link rewriting or footers it adds. You can also forward an email as an attachment from Gmail or Outlook. Treat the address like a password: replace it in Settings and the old one stops working at once.
Move your API integration
Here's how the core Email on Acid v5 calls map to EmailQA. The API is on the Business plan, with 3,000 renders a month shared with the app.
| Task | Email on Acid API v5 | EmailQA API v1 |
|---|---|---|
| Authenticate | Basic auth: API key and account password | Bearer token: Authorization: Bearer eq_… |
| List clients | GET /v5/clients | GET /api/v1/clients (no auth needed) |
| Create a test | POST /v5/tests with HTML and clients | POST /api/v1/projects with HTML, then POST /api/v1/projects/{slug}/renders with clients |
| Get results | GET /v5/tests/{test_id}/results | GET /api/v1/renders/{id}, or the signed render.completed webhook |
Full reference: EmailQA API docs. A typed client is on npm as emailqa.
FAQ
Can I keep my Email on Acid send-in address?
Plan to replace it. Mailgun's API migration plan says Inspect generates preview addresses through an API call instead of Email on Acid's static address, and EmailQA gives every account its own private address.
Does EmailQA support plus addressing like Email on Acid's +customer_id?
Yes. Text after a plus sign works as a label, and the email still arrives.
Which platforms can send to the EmailQA address?
Anything that can email an address: test sends from ESPs such as Loops, Braze, Iterable and Customer.io, marketing automation, transactional email, or a forward from Gmail or Outlook as an attachment.
Will my Email on Acid tests come with me?
No. Mailgun says existing tests and previews won't transfer to Inspect, so download anything you need before your account moves.
Does EmailQA have an API like Email on Acid's?
Yes, on the Business plan: $99 a month with 3,000 renders shared between the app and the API, signed webhooks and a TypeScript client. The table above maps the core calls.
Can clients and stakeholders review without an account?
Yes. Share the preview link and reviewers pin comments on the email without signing up; Pro adds approvals.
Does EmailQA do accessibility or spam testing?
No. If those checks are part of your sign-off, keep a QA suite such as Mailgun Inspect Premium for them and use EmailQA for real-device review.
Is there a free plan?
Yes: 25 real-device renders and 3 projects a month, with the send-in address included. Every account also starts with a 14-day Pro trial, no card required.
Sources
- Email on Acid is becoming Mailgun Inspect: what changes, and your options, EmailQA, September 23, 2026
- The next generation of email QA: Meet Mailgun Inspect, Mailgun, April 9, 2026
- Mailgun Inspect pricing, Mailgun
- Migrate from Email on Acid to Mailgun Inspect, Mailgun Help Center
- Email on Acid to Mailgun Inspect API Migration Plan, Mailgun Help Center
- Getting Started with the Mailgun Inspect Chrome Extension, Mailgun Help Center
- How to Use Email on Acid with Your ESP, Email on Acid
- EmailQA pricing, send a test email, real-device rendering, rendering API and API docs, EmailQA
Start a trial
EmailQA's 14-day Pro trial includes 50 renders and needs no card; run your last few campaigns through it alongside Email on Acid.
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