Comparison

Email on Acid vs GreenMail

No clear leader: Email on Acid (58.3) and GreenMail (58.2) are within the 5-point margin; treat as a tie. The attribute-by-attribute breakdown below, with a source and date on every value, is the honest way to compare them.

Machine formatsJSONMarkdownGraphQLor send Accept: application/json
Email on Acid58
GreenMail58
Score
Vioscale score
Email on Acid58 / 100medium · 66%updating
GreenMail58 / 100low · 31%updating
Pricing
Free tier
Email on Acid
GreenMail
Model
Email on Acidcommercial
GreenMailcommercial
Price level
Email on Acidhigh
GreenMailfree
Starting price
Email on Acid$99
GreenMail
Transparent
Email on Acid
GreenMail
Security
Gdpr
Email on Acid
GreenMail
Iso27001
Email on Acid
GreenMail
Scorecard
Email on Acid
GreenMail6.4
Soc2
Email on Acid
GreenMail
Reliability
Sla pct
Email on Acid99.9
GreenMail
Adoption
Dependent repos
Email on Acid
GreenMail2,587
Github stars
Email on Acid
GreenMail740
Activity
Commits last 30d
Email on Acid
GreenMail28
Release
Cadence days
Email on Acid
GreenMail43
History
Email on Acid
GreenMail20 items
License
Spdx
Email on Acid
GreenMailApache-2.0
Language
Primary
Email on Acid
GreenMailJava
Market
Availability
GreenMail

Capabilities

Feature-by-feature on the axes that matter for email testing dev. “-” means undocumented, not absent.

Capabilities
API assertions
Email on Acid
GreenMail
Rendering preview
Email on Acid
GreenMail
Spam score check
Email on Acid
GreenMail
Blocklist deliverability check
Email on Acid
GreenMail
SMS testing
Email on Acid
GreenMail
Production sending addon
Email on Acid
GreenMail
Ci cd integration
Email on Acid
GreenMail
Multi user inboxes
Email on Acid
GreenMail
Open source
Email on Acid
GreenMail

What each one is

The product in its own terms, so the numbers below have context.

Email on Acid

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.

Independently observed

GreenMail

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.

Independently observed

Pricing

List pricing as published by each vendor, with the date we read it. Always verify at the source before you buy.

Email on Acid

from $99/moSubscription7-day trial

From $99/month. 7-day free trial.

  • Basic$99/month, $0.15 per preview overage
    • 1,000 email previews per month
    • 100+ email preview clients and devices
    • Unlimited users
    • API access
    • Overage charges for additional previews
  • Premium$199/month
    • 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
    • +2 more
  • CustomContact sales
    • Custom preview allotments
    • Phone and chat support
    • Dedicated support documentation
as of verify ↗

GreenMail

Open sourceFree tier
as of verify ↗

Platform & deployment

Where each product runs and how it can be hosted. A dash means undocumented, not unsupported.

Platforms
Web
Email on Acid
GreenMail
Deployment
Cloud / SaaS
Email on Acid
GreenMail
Self-hosted
Email on Acid
GreenMail

Comparison generated from independently-sourced facts. Every value links to its source and retrieval date. See the method.