Email Spam Tester

You send one message to a disposable address and get back a report on why it might land in spam. The report covers SPF, DKIM, DMARC and ARC, the sending server's PTR and TLS, 21 blocklists, two separate spam engines, the HTML and links, and the Gmail and Yahoo rules for bulk senders. That comes to 42 checks. Every warning quotes the RFC it rests on, and the fix plan at the end is sorted by how many points each change wins back.

A second test shows which folder the message ends up in at different providers.

No account and no card. Developers can call the HTTP API without a key or connect an AI agent through the MCP server. The interface is in 31 languages.