# GreenMail vs Mailosaur

| Attribute | GreenMail | Mailosaur |
|---|---|---|
| **vioscaleAI score** | 55.9 (31% (low)) | 60.5 (56% (medium)) |
| activity.commits_last_30d | 30 | - |
| adoption.dependent_repos | 2,587 | - |
| adoption.github_stars | 747 | - |
| content.faq | `[{"answer":"A testing framework that emulates email server behavior (SMTP, POP3, IMAP) to help developers verify email functionality in their applications during testing, without requiring actual email infrastructure or sending real messages. It is indexed under Email Testing Dev.","source":"https://greenmail-mail-test.github.io/greenmail/","question":"What is GreenMail?","confidence":0.6},{"answer":"GreenMail is open source, so it can be self-hosted and used at no licence cost. It is released under the Apache-2.0 licence. Pricing changes often, so verify at source before relying on it.","source":"https://greenmail-mail-test.github.io/greenmail/","question":"Is GreenMail free to use?","confidence":0.6},{"answer":"Yes. GreenMail can be deployed self-hosted, so it does not have to run on the vendor's infrastructure.","source":"https://greenmail-mail-test.github.io/greenmail/","question":"Can GreenMail be self-hosted?","confidence":0.6},{"answer":"Yes. GreenMail is published under the Apache-2.0 licence, a permissive licence that generally allows commercial use and modification. Licence terms can change between releases, so verify against the repository for the version you intend to use.","source":"https://github.com/greenmail-mail-test/greenmail","question":"Is GreenMail open source?","confidence":0.95}]` | `[{"answer":"A testing service that validates email and SMS messages for accessibility standards compliance, rendering consistency across email clients, and delivery quality, with API and SDK support for automated testing. It is indexed under Email Testing Dev.","source":"https://mailosaur.com","question":"What is Mailosaur?","confidence":0.6},{"answer":"Mailosaur is a paid product; published pricing starts at $20 per month. It is sold across 3 plans (Personal, Core and Enterprise). There is no free tier. Prices are published openly on the vendor's own pricing page. Pricing changes often, so verify at source before relying on it.","source":"https://mailosaur.com/pricing","question":"How much does Mailosaur cost?","confidence":0.6},{"answer":"Mailosaur supports the web and iOS. Platforms we have not confirmed are simply not listed here rather than ruled out.","source":"https://mailosaur.com","question":"What platforms does Mailosaur support?","confidence":0.6},{"answer":"We have only confirmed a cloud / SaaS deployment for Mailosaur, so it appears to be vendor-hosted. If a self-hosted option exists we have not found it documented publicly.","source":"https://mailosaur.com","question":"Can Mailosaur be self-hosted?","confidence":0.6},{"answer":"We have confirmed 20 integrations for Mailosaur, including Selenium, Playwright, Cypress, TestCafe, WebdriverIO, Cucumber, Robot Framework and Ghost Inspector, plus 12 more. This is what we could verify from public sources, so the vendor may support others we have not indexed.","source":"https://mailosaur.com","question":"What does Mailosaur integrate with?","confidence":0.6},{"answer":"We have independently confirmed ISO 27001 and GDPR for Mailosaur. Certifications we do not list are ones we have not been able to verify from public sources, which is not the same as Mailosaur not holding them. Always confirm compliance directly before you rely on it.","source":"https://mailosaur.com/docs/compliance","question":"What security certifications does Mailosaur have?","confidence":0.7},{"answer":"Mailosaur is available worldwide. Its primary markets are the United Kingdom and the United States. The vendor is headquartered in the United Kingdom.","source":"https://mailosaur.com/pricing","question":"Where is Mailosaur available?","confidence":0.75}]` |
| deployment.options | `{"self_hosted":true}` | `{"cloud":true}` |
| description.long | GreenMail is a lightweight testing tool that simulates SMTP, POP3, and IMAP email servers for application testing. It allows developers to extract, verify, and modify test messages within a contained environment while supporting SSL encryption. | Mailosaur enables development and QA teams to test emails and SMS messages end-to-end with real-device message previews across email clients and devices. The platform supports test automation through APIs and integrations with popular testing frameworks, eliminating the need for dummy accounts or manual testing. |
| features.capabilities | `{"open_source":true,"sms_testing":false,"api_assertions":true,"spam_score_check":false,"ci_cd_integration":true,"rendering_preview":false,"multi_user_inboxes":true,"production_sending_addon":false,"blocklist_deliverability_check":false}` | `{"open_source":false,"sms_testing":true,"api_assertions":true,"spam_score_check":true,"ci_cd_integration":true,"rendering_preview":true,"multi_user_inboxes":true,"production_sending_addon":true}` |
| integrations.count | - | 13 |
| integrations.list | - | `[{"name":"Selenium"},{"name":"Playwright"},{"name":"Cypress"},{"name":"TestCafe"},{"name":"WebdriverIO"},{"name":"Cucumber"},{"name":"Robot Framework"},{"name":"Ghost Inspector"},{"name":"Postman"},{"name":"Insomnia"},{"name":"PowerShell"},{"name":"Node.js"},{"name":"Java"},{"name":"Python"},{"name":"Ruby"},{"name":".NET"},{"name":"PHP"},{"name":"Go"},{"name":"JavaScript"},{"name":"Okta"},{"name":"Microsoft Entra"}]` |
| language.primary | Java | - |
| license.spdx | Apache-2.0 | - |
| market.availability | - | `{"hqCountry":"GB","primaryMarkets":["GB","US"],"availabilityScope":"global","availableCountries":[],"notAvailableCountries":[]}` |
| platform.support | - | `{"web":true}` |
| pricing | `{"type":"open_source","freeTier":true,"sourceUrl":"https://greenmail-mail-test.github.io/greenmail/","retrievedAt":"2026-10-13T22:35:44.503Z"}` | `{"type":"subscription","plans":[{"free":false,"name":"Personal","summary":"$20/month billed annually","features":["Unlimited email addresses per inbox","Email compatibility testing","API for test automation","Email forwarding to external addresses"],"minSeats":1,"commitment":"annual","components":[{"kind":"fixed","amount":20,"period":"month","currency":"USD"}],"description":"Email testing essentials for individual developers","contactSales":false,"includedLimits":{"inboxes":"1","users_supported":"3","emails_per_month":"15000"}},{"free":false,"name":"Core","summary":"$50/month","features":["Multiple inboxes with unlimited email addresses","Team access and collaboration","Email accessibility testing","Email forwarding and reply functionality","POP3 and IMAP connectivity","Mail rules and auto-forwarding"],"minSeats":5,"commitment":"monthly","components":[{"kind":"fixed","amount":50,"period":"month","currency":"USD"}],"description":"Collaborative email testing for teams","contactSales":false,"includedLimits":{"seats_included":"5","emails_per_month":"75000"}},{"free":false,"name":"Enterprise","summary":"Custom pricing","features":["Custom user and inbox configuration","Team and project-level permission separation","Single Sign-On (SAML2 and OIDC)","Enterprise security features (SCIM, custom session timeouts)","Dedicated account manager","Advanced support with SLAs","Custom contract terms","International phone number support"],"description":"Custom solution for large organizations","contactSales":true}],"addOns":[{"name":"SMS and authentication","components":[{"kind":"fixed","amount":37.5,"period":"month","currency":"USD"}]},{"name":"Email previews","components":[{"kind":"fixed","amount":25,"period":"month","currency":"USD"}]}],"summary":"From $20/month billed annually. 14-day free trial available.","currency":"USD","freeTier":true,"sourceUrl":"https://mailosaur.com/pricing","retrievedAt":"2026-10-12T16:12:31.012Z","freeTrialDays":14,"startingPrice":{"amount":20,"period":"month","currency":"USD"},"billingPeriods":["month","year"]}` |
| pricing.free_tier | yes | yes |
| pricing.model | open_source | freemium |
| pricing.price_level | free | mid |
| pricing.starting_price | - | `{"amount":20,"currency":"USD"}` |
| pricing.transparent | - | yes |
| release.cadence_days | 29 | - |
| release.history | `[{"url":"https://github.com/greenmail-mail-test/greenmail/releases/tag/release-2.1.14","date":"2026-09-19T13:28:58Z","type":"stable","version":"release-2.1.14"},{"url":"https://github.com/greenmail-mail-test/greenmail/releases/tag/release-2.1.13","date":"2026-08-23T10:02:24Z","type":"stable","version":"release-2.1.13"},{"url":"https://github.com/greenmail-mail-test/greenmail/releases/tag/release-2.1.12","date":"2026-08-05T18:50:04Z","type":"stable","version":"release-2.1.12"},{"url":"https://github.com/greenmail-mail-test/greenmail/releases/tag/release-2.1.11","date":"2026-07-15T19:46:18Z","type":"stable","version":"release-2.1.11"},{"url":"https://github.com/greenmail-mail-test/greenmail/releases/tag/release-2.1.10","date":"2026-07-14T09:57:41Z","type":"stable","version":"release-2.1.10"},{"url":"https://github.com/greenmail-mail-test/greenmail/releases/tag/release-2.1.9","date":"2026-06-14T17:01:37Z","type":"stable","version":"release-2.1.9"},{"url":"https://github.com/greenmail-mail-test/greenmail/releases/tag/release-2.1.8","date":"2025-12-14T17:26:41Z","type":"stable","version":"release-2.1.8"},{"url":"https://github.com/greenmail-mail-test/greenmail/releases/tag/release-2.1.7","date":"2025-10-07T21:21:09Z","type":"stable","version":"release-2.1.7"},{"url":"https://github.com/greenmail-mail-test/greenmail/releases/tag/release-2.1.6","date":"2025-09-28T18:47:25Z","type":"stable","version":"release-2.1.6"},{"url":"https://github.com/greenmail-mail-test/greenmail/releases/tag/release-2.1.5","date":"2025-08-10T18:41:13Z","type":"stable","version":"release-2.1.5"},{"url":"https://github.com/greenmail-mail-test/greenmail/releases/tag/release-2.1.4","date":"2025-07-13T16:54:29Z","type":"stable","version":"release-2.1.4"},{"url":"https://github.com/greenmail-mail-test/greenmail/releases/tag/release-2.1.3","date":"2025-02-04T20:59:33Z","type":"stable","version":"release-2.1.3"},{"url":"https://github.com/greenmail-mail-test/greenmail/releases/tag/release-2.1.2","date":"2024-11-30T11:21:39Z","type":"stable","version":"release-2.1.2"},{"url":"https://github.com/greenmail-mail-test/greenmail/releases/tag/release-2.1.1","date":"2024-11-17T21:12:57Z","type":"stable","version":"release-2.1.1"},{"url":"https://github.com/greenmail-mail-test/greenmail/releases/tag/release-2.1.0","date":"2024-10-05T16:20:21Z","type":"stable","version":"release-2.1.0"},{"url":"https://github.com/greenmail-mail-test/greenmail/releases/tag/release-2.1.0-rc-1","date":"2024-05-31T20:05:52Z","type":"stable","version":"release-2.1.0-rc-1"},{"url":"https://github.com/greenmail-mail-test/greenmail/releases/tag/release-2.1.0-alpha-4","date":"2024-01-28T18:47:27Z","type":"stable","version":"release-2.1.0-alpha-4"},{"url":"https://github.com/greenmail-mail-test/greenmail/releases/tag/release-1.6.15","date":"2023-12-03T15:51:55Z","type":"stable","version":"release-1.6.15"},{"url":"https://github.com/greenmail-mail-test/greenmail/releases/tag/release-2.0.1","date":"2023-11-17T21:42:15Z","type":"stable","version":"release-2.0.1"},{"url":"https://github.com/greenmail-mail-test/greenmail/releases/tag/release-2.1.0-alpha-3","date":"2023-11-04T13:17:06Z","type":"stable","version":"release-2.1.0-alpha-3"}]` | - |
| security.certifications | - | `[{"name":"ISO 27001:2022","level":"2022","status":"active"}]` |
| security.disclosure_policy | - | yes |
| security.gdpr | - | yes |
| security.iso27001 | - | yes |
| security.pci | - | yes |
| security.scorecard | 6.6 | - |
| security.trust_center | - | https://mailosaur.com/security |
| security.vulnerabilities | `{"count":0,"source":"https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=maven&package_name=com.icegreen%3Agreenmail&per_page=100","last_12m":0,"max_severity":null}` | - |

## Capabilities (Email Testing Dev)

| Capability | GreenMail | Mailosaur |
|---|:--:|:--:|
| **Capabilities** |  |  |
| API assertions | ✓ | ✓ |
| Rendering preview | ✗ | ✓ |
| Spam score check | ✗ | ✓ |
| Blocklist deliverability check | ✗ | - |
| SMS testing | ✗ | ✓ |
| Production sending addon | ✗ | ✓ |
| Ci cd integration | ✓ | ✓ |
| Multi user inboxes | ✓ | ✓ |
| Open source | ✓ | ✗ |

*Source: vioscaleAI. Generated 2026-10-16T19:03:54.965Z. "-" = undocumented, not absent.*