Domain Health Check

The check command performs a comprehensive DNS audit of a domain, verifying SPF, DKIM, DMARC, MX, and PTR records.

Basic Usage

smtp-probe check example.com

What It Checks

Record	Description
SPF	Sender Policy Framework — which IPs/servers are allowed to send for this domain
DKIM	DomainKeys Identified Mail — cryptographic signing configuration
DMARC	Domain-based Message Authentication — policy for unauthenticated mail
MX	Mail Exchange records — which servers receive mail for this domain
PTR	Pointer record — reverse DNS lookup for the MX server IP

Scoring

Each check contributes to a 0–100 score. See Scoring System for the full deduction table.

Output Formats

# Default: colored terminal table
smtp-probe check example.com

# JSON
smtp-probe check example.com --format json

# Markdown
smtp-probe check example.com --format md

Interpreting Results

SPF examples:

✅ v=spf1 include:_spf.google.com ~all    ← Valid, soft fail
⚠️  v=spf1 +all                            ← Dangerous, allows any sender
❌ No SPF record                           ← Missing, -20 points

DMARC policy strength:

p=reject     ← Strongest, rejects unauthenticated mail
p=quarantine ← Moderate, quarantines unauthenticated mail
p=none       ← Weakest, monitoring only (-10 points if this is the only policy)

DNS Record Generator HTTP API