# Email on Acid vs GreenMail

| Attribute | Email on Acid | GreenMail |
|---|---|---|
| **Vioscale score** | 58.3 (66% (medium)) | 58.2 (31% (low)) |
| activity.commits_last_30d | - | 28 |
| adoption.dependent_repos | - | 2,587 |
| adoption.github_stars | - | 740 |
| deployment.options | `{"cloud":true}` | `{"self_hosted":true}` |
| description.long | Tests email campaigns across 100+ email clients and devices to identify rendering issues, validate content for inbox compatibility, check accessibility compliance, and detect deliverability problems before sending. | 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. |
| features.capabilities | `{"open_source":false,"sms_testing":false,"api_assertions":true,"spam_score_check":true,"ci_cd_integration":false,"rendering_preview":true,"multi_user_inboxes":false,"production_sending_addon":false,"blocklist_deliverability_check":true}` | `{"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}` |
| language.primary | - | Java |
| license.spdx | - | Apache-2.0 |
| market.availability | `{"primaryMarkets":["US"],"availabilityScope":"global","availableCountries":[],"notAvailableCountries":[]}` | - |
| platform.support | `{"web":true}` | - |
| pricing | `{"type":"subscription","plans":[{"free":false,"name":"Basic","summary":"$99/month, $0.15 per preview overage","features":["1,000 email previews per month","100+ email preview clients and devices","Unlimited users","API access","Overage charges for additional previews"],"commitment":"monthly","components":[{"kind":"fixed","amount":99,"period":"month","currency":"USD"},{"per":{"qty":1,"unit":"preview"},"kind":"metered","amount":0.15,"currency":"USD"}],"description":"Email preview testing with API access","contactSales":false,"includedLimits":{"previews":"1,000/mo","clients_devices":"100+"}},{"free":false,"name":"Premium","summary":"$199/month","features":["2,000 email previews per month","100+ email preview clients and devices","Unlimited users","Accessibility tests (WCAG 2.2 / European Accessibility Act compliance)","HTML code analysis","Link and image validation","Spam content checks across major ISPs"],"commitment":"monthly","components":[{"kind":"fixed","amount":199,"period":"month","currency":"USD"}],"description":"Full QA suite with accessibility testing and content analysis","contactSales":false,"includedLimits":{"previews":"2,000/mo","clients_devices":"100+"}},{"free":false,"name":"Custom","summary":"Custom pricing","features":["Custom preview allotments","Phone and chat support","Dedicated support documentation"],"description":"Custom preview allotments and enterprise support","contactSales":true}],"summary":"From $99/month. 7-day free trial.","currency":"USD","freeTier":false,"sourceUrl":"https://www.emailonacid.com/pricing/","retrievedAt":"2026-08-25T12:11:37.247Z","freeTrialDays":7,"startingPrice":{"amount":99,"period":"month","currency":"USD"},"billingPeriods":["month"]}` | `{"type":"open_source","freeTier":true,"sourceUrl":"https://greenmail-mail-test.github.io/greenmail/","retrievedAt":"2026-08-21T12:46:10.376Z"}` |
| pricing.free_tier | no | yes |
| pricing.model | commercial | commercial |
| pricing.price_level | high | free |
| pricing.starting_price | `{"amount":99,"currency":"USD"}` | - |
| pricing.transparent | yes | - |
| release.cadence_days | - | 43 |
| release.history | - | `[{"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"},{"url":"https://github.com/greenmail-mail-test/greenmail/releases/tag/release-2.1.0-alpha-2","date":"2023-08-20T20:17:02Z","type":"stable","version":"release-2.1.0-alpha-2"}]` |
| reliability.sla_pct | 99.9 | - |
| security.gdpr | yes | - |
| security.iso27001 | yes | - |
| security.scorecard | - | 6.4 |
| security.soc2 | yes | - |
| 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 | Email on Acid | GreenMail |
|---|:--:|:--:|
| **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: Vioscale. Generated 2026-09-01T17:11:16.701Z. "-" = undocumented, not absent.*