Email infrastructure
diagnostics & tools
Test DNS records, audit SPF/DKIM/DMARC, and get actionable fix advice. Built for mail operators and deliverability engineers.
Check your domain's email health
MX, SPF, DKIM, and DMARC — analyzed in one pass with actionable advice.
Your email toolkit
Diagnose, audit, and optimize email delivery with actionable advice
All protocols checked in one pass
Run MX, SPF, DKIM, and DMARC checks simultaneously and get a single health score. Issues are ranked by severity so you fix the most impactful problems first. No more switching between tools.
Run a full report →Deep authentication analysis
Validate SPF records against the 10-lookup limit, verify DKIM public keys and key strength, and parse DMARC policies with alignment checks. Each tool gives specific fix advice — not just pass/fail.
v=spf1 include:_spf.google.com
include:servers.mcsv.net ~all
See how your mail routes
Query MX records for any domain to see which servers handle its email. Check priority values, detect single-points-of-failure, resolve each server's IP and PTR record, and identify the mail provider.
Look up MX records →Trace delivery and check reputation
Paste raw email headers to trace every hop, check authentication results, and find delays. Look up any IP address to see its sending reputation, risk level, and 30-day volume trend.
Latest from the blog
Guides on email authentication, DNS, and deliverability
KumoMTA vs PowerMTA: A Deep Comparison for High-Volume Email Senders
An in-depth comparison of KumoMTA and PowerMTA covering architecture, performance, configuration, cost, and who each MTA is best suited for.
WP Mail SMTP Setup Guide for WordPress | InboxTooling
Step-by-step guide to configuring WP Mail SMTP in WordPress. Fix email delivery issues by routing WordPress emails through a proper SMTP server.
Why Are My Emails Going to Spam? 7 Causes and How to Fix Each One
Diagnose why your emails land in spam. Covers authentication failures, IP reputation, content triggers, list hygiene, and sending patterns with specific fixes.