Validate changes quickly
Run focused checks before and after DNS, certificate, or mail provider changes.
Diagnostic toolkit
Free Diagnostic Tools
Essential utilities for developers and system administrators. Debug email delivery issues, inspect domain security records, and map network ownership quickly.
SuperTool
One host. Every check.
Run SPF, DMARC, DKIM, email posture, MX, DNS, TLS, WHOIS, reverse DNS, and a blacklist sample for any domain or IP. Results stream in as each check completes, no signup required.
- SPF
- DMARC
- DKIM
- BIMI
- MTA-STS
- TLS-RPT
- MX
- DNS
- TLS
- WHOIS
- rDNS
- Blacklist
Pick a single tool
Each tool is optimized for a specific record, host, or email artifact so you can debug one signal without opening a dashboard.
- SPF SPF Record Checker Verify authorized senders, SPF syntax, and lookup risk before sender policy drift hurts deliverability.
- DMARC DMARC Analyzer Review DMARC policy, alignment mode, aggregate reporting destinations, and domain spoofing posture.
- TLS SSL Certificate Grade Grade certificate trust, hostname match, expiry, CAA, and observed TLS metadata for public endpoints.
- DNS DNS Lookup Resolve A, AAAA, MX, NS, CNAME, TXT, and related records when validating domain infrastructure.
- DKIM DKIM Record Checker Inspect DKIM selectors and public keys to confirm email signatures can validate correctly.
- BIMI BIMI Record Checker Check BIMI DNS records, logo references, and certificate signals used by supported inboxes.
- STS MTA-STS Policy Checker Validate MTA-STS DNS and policy files that protect inbound mail transport security.
- RPT TLS-RPT Record Checker Review TLS reporting destinations that help catch mail transport failures and downgrade attempts.
- MX MX Record Lookup Inspect mail exchangers and priorities when diagnosing inbound routing or provider changes.
- PTR Reverse DNS Lookup Check PTR records for sending IPs and infrastructure identity alignment.
- ASN ASN & IP Lookup Map an IP address to network ownership, ASN details, and address context.
- WHOIS WHOIS Lookup Review public registration, nameserver, and ownership signals available for a domain.
- HDR Email Header Analyzer Paste raw headers to inspect authentication results, routing hops, delays, and delivery context.
- SPF+ SPF Record Generator Build a valid SPF record from your senders and IPs, with a live DNS-lookup count and PERMERROR risk check.
- DMC+ DMARC Record Generator Assemble a correctly ordered DMARC record with policy, alignment, reporting, and percentage tags ready to publish.
- DK+ DKIM Record Generator Build the _domainkey record name and TXT template for any selector and key type, with guidance on publishing your public key.
- PROP DNS Propagation Checker Query Google, Cloudflare, Quad9, and OpenDNS in parallel to confirm whether a record has fully propagated or is still inconsistent.
- FLAT SPF Flattener Resolve an SPF record's full include chain and inline every ip4 and ip6 address into one record to cut DNS lookups below the PERMERROR limit.
- LOOK Lookalike Domain Checker Generate homoglyph, typosquat, and combosquat variants of your domain, then resolve each to flag which lookalikes are registered, accept mail, and pose a phishing risk.
Fast diagnostics before continuous monitoring
One-off checks are useful for triage. HostRepute turns the same operational signals into scheduled monitoring, alert routing, history, and team-ready reports.
Share findings clearly
Readable output helps support, engineering, and deliverability teams discuss the same evidence.
Escalate into monitoring
Move from one-off checks into scheduled scans, alert routing, history, and noindex reports.
Need alerts instead of manual checks?
Monitor hosts continuously across blacklist, DNS, TLS, SNDS, and Google Postmaster signals with clear alerts and shareable reports.