Mail-Tester

Mail-Tester gives senders a generated address, analyzes the received message, and returns a spam score with authentication and content diagnostics. It is not a full monitoring suite, but it is one of the simplest ways to catch obvious DNS, SpamAssassin, and content issues before a campaign sends.

At an early stage the deciding factors are what the free tier actually covers, what the first paid invoice looks like, and how much of a founding engineer's week the setup costs. Feature depth that only matters at a million sends a month is noise until it is not.

Against a waitlist, a launch announcement, onboarding email, and the first transactional sends, Mail-Tester covers developer experience, and does not cover scheduling, SDK breadth, and webhook coverage. Whether that gap matters depends on how central those are to the build.

• Free tier: 3 tests free within the last 24 hours via the web interface
• Best published rate per 1,000: Tiers not published in comparable form
• Starts at: $50 for 500 tests, or larger prepaid test packs
• DX score: 8/10
• Deliverability: Not a sender. Scores one message at a time and helps identify obvious authentication, blacklist, and SpamAssassin issues.
• Operating since: Not published
• Scheduling: No
• SDKs: None
• Webhooks: No

Not a sender. Scores one message at a time and helps identify obvious authentication, blacklist, and SpamAssassin issues.

Developers and marketers who need a quick preflight check for a specific message.

Teams that need continuous DMARC monitoring or inbox placement reporting.