Email Spam Tester analyses a single email message and reports what a receiving mail server sees. The user copies a disposable address from the site, sends the message to it from their own sending platform, and receives a report a couple of minutes later. Reports have permanent links and are readable in 31 languages.
The 41 checks are grouped into authentication (SPF, DKIM, DMARC and ARC, including alignment with the From domain), infrastructure (reverse DNS, HELO, MX, TLS, 21 DNS blocklists), two independent spam engines (one reproducing the SpamAssassin scoring model), content (HTML structure, images versus text, link reputation, list-unsubscribe headers), the bulk sender requirements Gmail and Yahoo enforce since 2024, and an advisory group (BIMI, MTA-STS, TLS-RPT, DNSSEC) that never affects the score.
Two scores are produced: a classic 0 to 10 comparable with SpamAssassin-based testers, and a 0 to 100 score that weights authentication and infrastructure more heavily. Each warning or failure cites the section of the relevant RFC and, where one exists, the receiver's own published requirement. A fix plan lists changes in order of effect, with the score recomputed for the corrected message.
The service has no accounts. An API without keys, an MCP server for AI agents and an agent skill file are provided. The first 100,000 reports are free for everyone. Email Spam Tester is a free, independent email deliverability testing tool built by Serhii Tanichev.
Serg Tanichev added Email Spam Tester as alternative to mail tester and Mailchecker
No comments or reviews, maybe you want to be first?