Mailosaur does more.
You might need less.

Mailosaur is the mature incumbent: client previews, enterprise SSO, SMS numbers beyond the US. If your suite creates an inbox, waits for an OTP, and asserts — you're paying for a lot of product you'll never call. Here's the honest breakdown.

unlimited seats on every tier, including Free
CHOOSE MAILFIXTURE IF
CHOOSE MAILOSAUR IF

The numbers, side by side

Their listed prices assume annual billing (monthly runs about 20% higher). Ours are just the price.
MAILFIXTUREMAILOSAUR
Free plan 100 messages/mo, forever 14-day trial
Entry paid plan $15/mo, month to month $20/mo, billed annually
Users on the entry plan Unlimited 1 user included
A team of five $49/mo — Team, unlimited users $50/mo — Core, 5 seats, annual
Messages included at entry 2,500/mo, then $3.50 per extra 1k 15,000/mo (500/day cap)
MCP server for AI agents Built in — remote, every plan No official server (community wrappers)
SMS testing US numbers, included on paid plans Add-on from $37.50/mo — numbers beyond the US
SPF/DKIM/DMARC on received mail Automatic on every message (extracted.auth) Yes — on-demand deliverability report per message
Email client previews No Yes, add-on from $25/mo
Sends mail from its infrastructure Never — receive-only by design Yes: reply, forward, POP3/IMAP
mailosaur numbers from mailosaur.com/pricing, sms from mailosaur.com/sms-testing, mcp status from mailosaur.com/docs, deliverability report from mailosaur.com/docs/api/analysis — re-checked jul 7, 2026. if they've changed, trust their pages over ours.

Read the table honestly

Rows up there still favor Mailosaur, and we left them in. Their entry plan includes six times our entry volume — if your suite genuinely receives thousands of messages a day from one seat, their Personal plan is strong value. Client previews are a real capability we don't have and aren't building. And on SMS — which we now do — their coverage is broader: our numbers are US-only, theirs reach other countries. If your app verifies phones in Berlin, they win that row too.

The rows that favor us are about shape, not size. Test tooling gets used by whoever is debugging the flaky signup spec at 6pm — per-seat pricing means that person might not have a login. On MailFixture everyone gets their own sign-in, on every plan: invite the whole team and each person signs in with their own magic link. A QA inbox with a bouncer at the door helps nobody.

And the last row is a philosophy, not a feature gap. Mailosaur can reply and forward because their customers asked for it — legitimate uses exist. We refuse to ship an SMTP client at all: mail comes in, never out. Our IPs can't land on a spam blocklist, and no bug of ours can ever send email with your domain on it. For a tool that exists to absorb your production email flows, we think that guarantee is worth more than the features it costs us. It's also why we can charge $3.50 per 1,000 messages for overage instead of cutting you off mid-run.

What migrating actually looks like

The concepts map one-to-one: a Mailosaur server becomes a MailFixture domain, an email address becomes an inbox, and your polling loop becomes a long-poll the server holds open. Same test, fewer moving parts:

signup.spec.ts · Playwright
const mail = new MailFixture(); // reads MAILFIXTURE_API_KEY

const inbox = await mail.createInbox({ ttlSeconds: 900 });
await page.fill('#email', inbox.address);
await page.click('text=Send code');

const otp = await inbox.waitForOtp({ timeout: 30_000 }); // server-side long-poll
await page.fill('#otp', otp);

Fair questions

Is MailFixture a drop-in replacement for Mailosaur?
No — the concepts map (servers become domains, email addresses become inboxes) but the APIs differ. Most suites migrate in an afternoon: swap the client, replace polling with waitForOtp, keep your assertions.
Does MailFixture test SMS?
Yes, as of July 2026 — dedicated US phone numbers on paid plans, with the same long-poll and OTP extraction as email. The honest caveats: US numbers only, receive-only (no sending, no short codes, no MMS), and the monthly SMS quota is a hard stop on every plan. If you need codes on non-US numbers, Mailosaur covers more countries.
Why is MailFixture so much cheaper?
Scope again. No sending infrastructure, no client-preview farm, no seat accounting. Receiving and parsing email is all we do, and the unit we charge for is the message — not the person reading it.
100 messages/mo free · no card · no seats to count
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