GreenMail vs Maildev
No leader: the top candidate Maildev has only 0.24 confidence (low), below the 0.35 needed to declare a winner. The attribute-by-attribute breakdown below, with a source and date on every value, is the honest way to compare them.
Capabilities
Feature-by-feature on the axes that matter for email testing dev. “-” means undocumented, not absent.
What each one is
The product in its own terms, so the numbers below have context.
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.
Maildev
Runs as a local SMTP server with a web inbox interface to capture and review emails generated by your application during development. Supports AI agent integration through the Model Context Protocol for automated email inspection.
Pricing
List pricing as published by each vendor, with the date we read it. Always verify at the source before you buy.
Platform & deployment
Where each product runs and how it can be hosted. A dash means undocumented, not unsupported.
Comparison generated from independently-sourced facts. Every value links to its source and retrieval date. See the method.