A free Mailosaur alternative for email verification in tests

Mailosaur is a paid email + SMS testing platform for QA teams. If you only need to read a verification email in an automated test, receivemail.dev does that free with no signup.

Mailosaur is a polished, paid testing platform: dedicated email servers, a real domain per account, SMS testing with virtual numbers, deep assertions (SPF/DKIM/DMARC checks, spam scoring, link and attachment inspection), and first-party libraries for most test frameworks. For a QA team that tests email and SMS seriously, it's a strong tool and this page isn't trying to move you off it.

Plenty of projects, though, only need one thing from a tool like this: in an automated test, sign up and read back the verification email. For that, receivemail.dev does the job with no account and no cost — you create a disposable inbox with one unauthenticated POST and poll it for messages.

Side by side

	receivemail.dev	Mailosaur
Price	Free	Paid, with a free trial (check current pricing)
Signup / account	None	Required
Receive email via API	Yes	Yes
SMS / phone testing	No (see sms-florin)	Yes
Dedicated domain per account	No — shared domain, random address	Yes
Email auth checks (SPF/DKIM/DMARC), spam score	No	Yes
Official framework libraries	No — plain HTTP (plus a Playwright helper)	Yes, many
Inbox lifetime	Up to 60 min TTL	Persistent
Best for	Reading a code/link in CI, hobby projects, OSS	QA teams testing email & SMS as a discipline

Mailosaur's plans and limits change over time — see mailosaur.com/pricing for current details.

When receivemail.dev is enough

• The assertion you actually make is "a message arrived and it contains this code/link" — nothing about headers, deliverability, or spam.
• You don't want another paid tool in the stack for one test.
• Contributors should be able to run the suite without credentials.
• It's a side project, a demo, or an open-source repo's CI.

When to choose Mailosaur instead

• You test SMS and email and want them in one tool.
• You assert on SPF/DKIM/DMARC, spam score, or rendered HTML.
• You want a dedicated domain and persistent inboxes.
• You want vendor-supported libraries and a support contract.
• Deliverability itself is under test, not just message content.

Migrating a test

# Mailosaur: new MailosaurClient(key); server + messages.get(...)
resp=$(curl -s -X POST https://receivemail.dev/mailboxes)
addr=$(echo "$resp" | jq -r .address)
secret=$(echo "$resp" | jq -r .secret)

# ... run your signup against $addr ...

curl -s "https://receivemail.dev/mailboxes/$addr/messages" \
  -H "Authorization: Bearer $secret"
# => {"messages":[{"from_address":"...","subject":"...","body_text":"..."}]}

Playwright version and more detail: the CI testing guide.

Other alternatives people compare

• MailSlurp — email infrastructure API, send + receive. See the MailSlurp comparison.
• Mailinator — free public inboxes, paid private domains + API. See the Mailinator comparison.
• Self-hosted (Mailpit, MailHog) — ideal when your own app sends the mail on the same network; not an option when a third party sends to a public address.