Deliverability tools

See your message’s spam score before you send — from the subject and body.

The engine analyses the content with SpamAssassin-style rules and returns a numeric score — lower is better, 5.0 is the spam threshold. Paste the subject and body (or HTML) to catch spammy words, a bad text-to-image ratio, broken markup and other signals before a real send. Remember: content is only part of it — authentication (SPF/DKIM/DMARC) and IP/domain reputation are covered by the SMTP diagnostics.

Via API: POST /api/v1/tools/spam-score {"subject":"…","text":"…"}

Check an IP or domain against the major blocklists (DNSBL).

A single listing on Spamhaus, Barracuda or SpamCop can wreck deliverability — mail goes to spam or bounces outright. This tool queries the major DNSBLs and shows where you’re listed. Check your sending IP and domains regularly, and if you’re listed, fix the cause and request delisting on the list’s own site.

Via API: POST /api/v1/tools/blocklist {"ip":"…"}

Live check of a domain’s mail server: MX, connection, STARTTLS, SPF/DMARC.

We look up the domain’s MX records, connect live to the primary server on port 25, read the greeting banner, ask for the ESMTP extension list and check STARTTLS (channel encryption) support. We also check whether SPF and DMARC are published. It’s a fast way to confirm the domain accepts mail, the server is reachable and TLS is configured — no manual telnet needed.

Via API: POST /api/v1/tools/smtp-diagnostics {"domain":"…"}