MailTester vs testmail.app

MailTester checks why email may reach spam and returns a deliverability score out of 10. To run a test, generate a disposable address, send the message there and receive a report in seconds. Scoring starts at 10, subtracts points for detected issues, and explains penalties with suggested fixes. Authentication checks include SPF, DKIM, DMARC, domain alignment, reverse DNS and forward-confirmed reverse DNS. Sending IPs are checked against Spamhaus, SpamCop, Barracuda and other DNS blocklists. Content analysis covers HTML, text-to-image ratio, links, subject, List-Unsubscribe and Message-ID. Rspamd supplies a spam score and triggered rules. Newsletter checks include one-click List-Unsubscribe under RFC 8058, message size and text-image ratio. MailTester offers web, API and self-hosted platforms. Its API creates test addresses and reads report status and scores as JSON. The free plan costs nothing, needs no account and provides 25+ checks per test.

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.