Compare and switch
InboxSpec vs testmail.app
A dated comparison of volume pricing, live queries, extraction and custom domains, including where testmail.app is better.
Checked on 24 October 2026
Every testmail.app fact on this page comes from its public pricing page and documentation on that date, listed under Sources. Prices and plans change, so check their current pages before deciding. If something here is wrong or out of date, tell us at hello@inboxspec.com and we will correct it.
At a glance
| Topic | testmail.app | InboxSpec |
|---|---|---|
| Price, monthly billing | Free $0, Essential $12, Pro $39, Enterprise $129, Unlimited $299. Annual billing lowers these to $9, $29, $89 and $269 a month. | Free $0 (500 messages/month), Starter $19 (10,000), Developer $49 (50,000), Team $129 (150,000). Monthly billing only. |
| Volume | 100, 10,000, 50,000, 1,000,000 and 10,000,000 emails/month. Paid limits are soft: temporary surges cost nothing extra. | 500, 10,000, 50,000 and 150,000 messages/month, with optional paid overage. |
| Custom receiving domain | Unlimited plan ($299 a month, or $269 billed annually). | Shared domain on Free. Custom receiving domains on every paid plan: 1 on Starter, 3 on Developer, 10 on Team. |
| People | Unlimited users on every plan. | No per-seat fees on any plan. Every plan has the same fair-use ceiling of 1,000 people per workspace. No per-inbox, per-request or MCP charge. |
| Waiting | A live query holds the request and then redirects to itself every minute. There is no timeout parameter, so the test suite has to impose its own limit. | POST /v1/messages/wait blocks on the server for up to 285 seconds per call (default 120). Waiting is not metered and not rate limited; concurrent-wait limits apply. |
| Codes and links | Not extracted. Its examples use a regular expression over the body. | The wait response already contains ranked codes and links classified as verify, sign_in, reset_password, unsubscribe or other. |
| Deleting mail | No delete function. Mail expires after 1, 3 or 30 days depending on plan. | Delete a message or inbox, or clean up a whole run by tag. |
| Capture outgoing mail | Not offered. Mail arrives at its public MX. | Capture SMTP with STARTTLS on port 587 on every plan, including Free. |
Where testmail.app is the better choice
- It is cheaper for volume. 50,000 emails costs $39 a month against InboxSpec's $49, and 1,000,000 costs $129 against InboxSpec Team's 150,000.
- Soft limits: an occasional surge does not cost extra or get refused.
- Unlimited users on every plan, and addresses that need no registration.
- A GraphQL API that returns only the fields you ask for, and annual discounts.
- Its plan named Enterprise lists SSO and a 99.99% uptime SLA.
Where InboxSpec differs
- A custom domain from $19 a month rather than $269.
- A wait with an explicit timeout and a timeout result, instead of a redirect loop that only the test suite can stop.
- Codes and classified links in the wait response, capture SMTP for outgoing mail, and hosted MCP.
Some limits apply to InboxSpec whichever tool you compare it with:
- InboxSpec is new. Production opened in October 2026, so it has no long operating record.
- It only receives and captures email. It does not send to real recipients, test SMS, render emails in real mail clients or offer annual billing.
- It has no SSO, SOC 2 report or uptime SLA.
- REST and hosted MCP are public. The TypeScript SDK and CLI are reviewed release archives that are not yet on a public package registry.
Sources
All pages read on 24 October 2026. InboxSpec figures come from the pricing page and the wait guide.
Mailosaur, MailSlurp, testmail.app and Mailtrap are trademarks of their owners. InboxSpec is not affiliated with them.