Mailosaur
Platform for testing email and SMS communications end-to-end before production
- Also known as
- mailosaur
Available worldwide · Popular in: GB, US
What is Mailosaur?
Provides tools for validating emails and SMS messages through dedicated inboxes and phone numbers, with rendering previews across devices and email clients, integration into CI/CD pipelines, and automation via APIs and testing framework support.
Mailosaur pricing
Plans, per-tier features and add-ons, dated and linked to live pricing. Pricing changes often; always verify at source before you rely on it.
From $20/month (billed annually). Free 14-day trial.
Personal
For individuals requiring email testing essentials
- users
- 1 (support for up to 3)
- inboxes
- 1
- emails_per_month
- 15,000
- Email compatibility testing
- API for test automation
- Forward emails to external addresses
Core
Collaborative testing scaled for teams
- users
- 5 seats
- emails_per_month
- 75,000
- Team access
- Multiple inboxes
- Email accessibility testing
- Mail rules
- POP3/IMAP connectivity
- SMS support
Enterprise
Contact sales- Custom users and inboxes
- SSO (SAML2/OIDC)
- Separate permissions
- Enterprise security
- Account manager
- Advanced support with SLAs
Add-ons
- SMS and authentication$37.50/mo
- Email previews$25/mo
What Mailosaur does
The capabilities that matter for email testing dev, normalised so it lines up with every alternative. “-” means we haven't confirmed it, not that it's missing.
- API assertions
- ✓
- Rendering preview
- ✓
- Spam score check
- ✓
- Blocklist deliverability check
- -
- SMS testing
- ✓
- Production sending addon
- -
- Ci cd integration
- ✓
- Multi user inboxes
- ✓
- Open source
- -
Platform & deployment
Independently observed- CLI
- Web
- Cloud / SaaS
Integrations (21)
Independently observed- Selenium
- Playwright
- Cypress
- TestCafe
- WebdriverIO
- Cucumber
- Robot Framework
- Ghost Inspector
- Postman
- Insomnia
- PowerShell
- Node.js
- Java
- Python
- Ruby
- .NET
- PHP
- Go
- JavaScript
- Okta
- Microsoft Entra
Mailosaur alternatives
Other email testing dev we track, ranked by the same independent score.
- Testmail.appProgrammable email testing service for developers and QA automating end-to-end test verificationlow · 42%
- Maildevlow · 24%
- Email on AcidEmail testing and validation platform for pre-send campaign quality assurancemedium · 66%
- GreenMaillow · 31%
- MailSlurpOn-demand email and SMS testing platform for developersmedium · 54%
- MailHoglow · 19%
Compare Mailosaur
Side by side against other email testing dev, attribute by attribute, with a source on every value.
The Vioscale score: one lens on the evidence
Not user reviews and not a paid placement: a confidence-weighted blend of the independent signals below (adoption, activity, security posture, and more), which you can sort and re-weight yourself. Vendors can correct their listing but can never move their rank, and stars are weighted low as a vanity metric. It is one way to read the evidence for Mailosaur, not the verdict.
| Signal | Score | Weight | Contribution | Evidence |
|---|---|---|---|---|
| Pricing transparency | 75 | 0.08 | 6.3 | ✓ |
| Capabilities | 81 | 0.05 | 4.0 | ✓ |
| Security posture | 50 | 0.07 | 3.7 | ✓ |
| Price level | 50 | 0.05 | 2.6 | ✓ |
| Integrations | 38 | 0.04 | 1.5 | ✓ |
| Reliability | 0 | 0.07 | 0.0 | - |
Computed . Re-weight it by intent, or see the full method.
All data & sourcesshow ↓
Every value we hold, with its source, retrieval date, and confidence. This is the evidence behind the score: don't trust it, verify it.
Features
| Attribute | Value | Evidence |
|---|---|---|
| Capabilities | Sms testing, Api assertions, Spam score check, Ci cd integration, Rendering preview, Multi user inboxes | mediumsource · 2026-08-25 · 60% |
Integrations
| Attribute | Value | Evidence |
|---|---|---|
| Count | 20 | mediumsource · 2026-08-25 · 60% |
Market
| Attribute | Value | Evidence |
|---|---|---|
| Availability | HqCountry: GB · PrimaryMarkets: … · AvailabilityScope: global · AvailableCountries: … · NotAvailableCountries: … | highsource · 2026-08-25 · 75% |