| Tool | Cost | Account | Read mail via API | Inbox privacy | Retention |
|---|---|---|---|---|---|
| receivemail.dev | Free, no signup; Pro $7/mo | None | Yes, no key needed | Private (per-mailbox secret) | Free 60 min, Pro 24 h |
| mail.tm | Free, no paid tiers | None (mailbox created via API) | Yes, no key; 8 req/s per IP | Private (password) | Not published |
| Mailsac | Free 1,500 ops/mo; from $18/mo | For API key / private inbox | Yes, with key | Public without account; 1 private address free | Plan-dependent |
| Mailinator | Public inboxes free; Verified Pro $0 on approval; Business $79/mo (yearly) | For private inboxes / API | Not on the public tier | Public, unless on a private domain | Temporary on the public tier |
| Mailosaur | No free plan; 14-day trial, from $20/mo (yearly) | Required | Yes, with key | Private (own server/domain) | Persistent |
| testmail.app | Free 100 emails/mo; from $9/mo (yearly) | Required | Full API from the $9 plan | Private namespace | Free 1 day |
| Mailpit | Free, self-hosted | None (you run it) | Yes (REST) | Your own server | Your choice |
Checked against each vendor's pricing and docs pages on 26 October 2026. Plans change — confirm on their sites before you commit. Mailpit only catches mail your own app sends to it over SMTP; it can't receive from a third-party service sending to a public address.
MailSlurp is a full email-infrastructure API — it can send and receive, gives you SMTP/IMAP access, permanent inboxes, custom domains, attachments, phone numbers, team accounts and a SOC 2 option. If you need that, MailSlurp is a solid choice and this page won't talk you out of it.
But a lot of people reach for MailSlurp for one narrow job: in an automated test, sign up for something and read the verification email back. For that job specifically, you don't need an email platform — you need a throwaway address you can poll. That's all receivemail.dev does, and it does it free with no signup.
| receivemail.dev | MailSlurp | |
|---|---|---|
| Price | Free; Pro $7/mo (24 h inboxes, extracted codes) | Free plan (100 inbox creations, 500 received emails / mo), paid from $19.99/mo |
| Signup / account | None | Required |
| API key to create an inbox | No | Yes |
| Receive email via API | Yes | Yes |
| Send email | No | Yes |
| SMTP / IMAP access | No | Yes |
| Permanent inboxes | No — up to 60 min free, 24 h on Pro | Yes |
| Custom domains | No | Yes (paid) |
| Phone / SMS | No (see sms-florin) | Yes |
| Rate limit | 20 inbox creations / min per IP | Plan-dependent |
| Hosting | Cloudflare Workers | Managed SaaS |
MailSlurp's exact free-tier limits and plan prices change over time — check mailslurp.com/pricing for the current numbers.
If your test currently does "create MailSlurp inbox → sign up → wait for email", the receivemail.dev version is:
# create a mailbox — no key, no account
resp=$(curl -s -X POST https://receivemail.dev/mailboxes)
addr=$(echo "$resp" | jq -r .address)
secret=$(echo "$resp" | jq -r .secret)
# ... run your signup against $addr ...
# poll for the verification email
curl -s "https://receivemail.dev/mailboxes/$addr/messages" \
-H "Authorization: Bearer $secret"
# => {"address":"...","messages":[{"from_address":"...","subject":"...","body_text":"..."}]}
There's a fuller walkthrough (shell + Playwright) in the CI testing guide.
Yes. receivemail.dev and mail.tm both create a private inbox over the API with no account and no API key. MailSlurp itself has a free plan (100 inbox creations and 500 received emails a month), but it needs an account.
If the test only signs up and reads back a verification code or link, yes. If it sends email, needs inboxes that persist for days, SMTP/IMAP or custom domains, stay on MailSlurp.
On the $7/mo Pro plan each message comes back with the code already extracted in an otp field; the $19/mo plan adds webhooks. The free tier returns the raw subject and body. See the OTP guide.