mailX

mailX is a free email deliverability and DNS diagnostic toolkit that helps teams see why emails hit spam and how to fix technical issues. It combines live DNS lookups, SPF, DKIM, DMARC and blacklist checks with clear, human readable guidance. Both humans and AI agents can run audits in seconds from the browser, an API or an MCP server.

What is mailX? mailX is a free email deliverability and DNS diagnostic toolkit that helps teams see why emails hit spam and how to fix technical issues. It combines live DNS lookups, SPF, DKIM, DMARC and blacklist checks with clear, human readable guidance. Both humans and AI agents can run audits in seconds from the browser, an API or an MCP server. Key Features: Combined deliverability audit: Runs SPF, DKIM, DMARC, MX and blacklist checks together for a domain or IP and returns one prioritized report. Real time DNS and mail server tools: Provides DNS lookup, propagation checks, MX, TXT, CNAME and PTR queries, plus SMTP and IMAP tests and SPF/DMARC/DKIM generators built on live DNS. Plain language issue explanations: Translates dense DNS and authentication details into short descriptions and copy paste ready records so non specialists can correct problems quickly. MCP and JSON API for AI agents: Exposes each checker and a higher level deliverability audit through an MCP server and JSON responses that tools and agents can call programmatically. Pros Time Efficiency: One click audits replace juggling multiple separate DNS and deliverability tools. Accessibility for non engineers: Plain explanations and suggested records help founders and marketers fix problems without deep DNS knowledge.