MailHog vs testmail.app

MailHog is a free email testing tool for developers. Applications send mail to it over SMTP, after which users can inspect messages in a web interface or retrieve them through a JSON API. The interface displays plain text, HTML or source, supports encoded headers and updates in real time. The API can list, retrieve and delete messages, and download complete messages or individual MIME parts. Messages may also be released to real SMTP servers. MailHog supports ESMTP RFC5321, SMTP AUTH and PIPELINING, and includes a Chaos Monkey feature for failure testing. Storage defaults to memory, with MongoDB and Maildir also available. It can run from the command line, as a daemon, in Docker or on AWS Elastic Beanstalk. Its default SMTP and HTTP ports are 1025 and 8025. In-memory storage limits Elastic Beanstalk deployments to one instance; load-balanced deployments require MongoDB-backed storage. MailHog is released under the MIT license.

testmail.app receives, parses, spam-tests, and indexes test emails for automated end-to-end testing. Messages sent to addresses such as `{namespace}.{tag}@inbox.testmail.app` are routed into mailboxes, allowing tests to create addresses and mailboxes dynamically. The service provides simple JSON and GraphQL APIs, with client examples for JavaScript, PHP, Ruby, Python, Go, Bash, C#, and Java. Search includes wildcard queries, live waits for new mail, sorting, pagination, attachments, and SpamAssassin reports. GraphQL adds advanced filters, field selection, and custom sorting unavailable in the simple JSON API. Documented integrations cover Cypress, Selenium, TestCafe, and email OTP testing. New accounts receive a 14-day trial without a credit card, then move to the free plan. Free includes 100 emails monthly and one-day retention. Paid plans start at $9/mo (annual). Hosting uses AWS, with encrypted data and passwordless logins.