If you manage more than one domain — whether you're an agency, an MSP, a domain investor, or run multiple SaaS products — you know the pain of checking email deliverability one domain at a time. It's slow, repetitive, and error-prone.
By the time you've checked domain #7, domain #3's SPF record might have expired and you wouldn't know it. This guide shows you how to audit multiple domains simultaneously, what to look for, and how to prioritize fixes.
🔍 Audit Your Domains Now — Free
Paste your domain list and get deliverability scores for all of them in seconds. 3 domains free, no signup.
Open Bulk Domain Checker →Why Bulk Domain Auditing Matters in 2026
Email deliverability requirements have tightened significantly. Google and Yahoo now require SPF, DKIM, and DMARC for any domain sending more than 5,000 emails per day. Even for lower volumes, missing authentication records means your transactional emails, password resets, and customer communications risk landing in spam.
If you manage multiple domains, the risk multiplies. One misconfigured domain can:
- Silently lose customer emails — no bounce notification, just a spam folder burial
- Damage your overall sender reputation — especially if domains share infrastructure
- Get your IP blacklisted — affecting all domains on that IP
- Miss compliance deadlines — Google and Yahoo enforcement is ongoing throughout 2026
What a Bulk Domain Audit Checks
Our bulk checker runs the same comprehensive analysis for every domain you provide. Here's exactly what gets checked per domain:
| 📬 MX Records | How many mail servers are configured? Are they reachable? Missing MX = email can't be received. |
| 🛡️ SPF Record | Which servers are authorized to send email from this domain? Missing SPF = anyone can spoof you. |
| 🔐 DKIM Signature | Is the domain cryptographically signing outgoing mail? Missing DKIM = no tamper protection. |
| 📊 DMARC Policy | What should receivers do with unauthenticated mail? Missing DMARC = no enforcement. |
| 🚫 Blacklist Status | Is the domain or its MX IPs on Spamhaus, SpamCop, Barracuda, SORBS, or PSBL? Even one blacklist hit can tank deliverability. |
How to Run a Bulk Domain Audit (Step by Step)
Step 1: Prepare Your Domain List
Gather every domain you want to audit. The tool accepts domains one-per-line or comma-separated. Examples:
client1.com
client2.org
my-saas-product.io
side-project.dev
Pro tip: Export your domain list from your registrar, Cloudflare dashboard, or spreadsheet. The tool strips whitespace and ignores empty lines automatically.
Step 2: Paste Into the Bulk Checker
Go to the bulk domain checker and paste your list. Hit "Check All Domains." The engine resolves every DNS query in parallel, so even large lists complete in seconds.
Step 3: Scan the Color-Coded Results
Each domain gets an instant color-coded score:
Red domains need your attention first. Yellow domains are functional but fragile. Green domains are production-ready.
Step 4: Deep-Dive Into Problem Domains
Click any domain card for a full deliverability audit — all DNS records, blacklist details per IP, and specific fix recommendations. The deep-dive page shows you exactly which records are missing and how to add them.
Step 5: Export and Track (Pro)
Pro users (€9/month) get CSV export of all results and unlimited domains per check. Agencies use this to generate monthly deliverability reports for clients automatically.
Manual vs Bulk: Time Comparison
| Method | 10 Domains | 50 Domains | 100 Domains |
|---|---|---|---|
| Manual (one-by-one) | ~30 min | ~2.5 hours | ~5 hours |
| Bulk Checker | ~5 sec | ~15 sec | ~25 sec |
That's not an exaggeration. The bulk checker resolves DNS in parallel. What takes a human 5 hours is done before you can pour a coffee.
Who Needs Bulk Domain Auditing?
🏢 Agencies & MSPs
Monitor email deliverability across all client domains in one dashboard view. Run weekly audits before client check-ins. Flag domains that need attention before clients notice problems.
📦 Domain Investors & Portfolio Holders
Quickly audit MX, SPF, and DMARC status across parked and monetized domains. Identify which domains have active mail configuration and which are dormant. Make informed decisions about domain sales.
🚀 SaaS Companies & Startups
Check your main product domain, marketing site, docs subdomain, status page, and blog — all at once. Ensure every customer-facing domain is email-ready. One missing SPF record can mean lost signups.
📊 Email Deliverability Consultants
Run batch audits before client meetings. Compare deliverability scores across client portfolios side by side. Generate professional reports with exportable data.
Common Issues Found in Bulk Audits
After running thousands of bulk checks, here are the patterns we see most often:
- Missing DMARC (most common) — ~60% of domains have no DMARC policy at all. It takes 2 minutes to add one with our free DMARC generator.
- Stale SPF includes — Domains reference email providers they stopped using years ago (old Google Workspace, decommissioned SendGrid accounts).
- No MX on parked domains — Expected, but worth knowing. If you plan to sell a domain, a buyer will want to know.
- Single MX without backup — One mail server with no failover. If that server goes down, email is lost.
- Blacklist surprises — A domain you haven't touched in months is suddenly on Spamhaus because a shared IP got flagged.
📋 Ready to Audit Your Domains?
Paste your domain list below and get instant deliverability scores. No signup. No ads. 100% free for up to 3 domains.
Launch Bulk Checker →Going Pro: Automated Monitoring
One-off audits are great, but email configuration drifts. Your SPF record was perfect three months ago — but did someone on your team change DNS without updating it? Did a new marketing tool get added without authorization?
The Pro plan (€9/month) adds continuous monitoring:
- Unlimited domains per bulk check
- CSV export for reporting and spreadsheets
- API access for integrating checks into your own tools
- Priority DNS resolution for faster results
FAQ
Is the bulk domain checker really free?
Yes. Free tier: 3 domains per bulk check, unlimited times. No signup, no ads, no credit card. Pro plan (€9/month) removes the domain limit and adds CSV exports and API access.
How accurate are the deliverability scores?
Scores are based on live DNS resolution against real public resolvers. MX (30 pts), SPF (25 pts), DKIM (15 pts), DMARC (15 pts), and blacklist status (15 pts) are weighted and summed. A score of 100 means all checks passed — the domain is well-configured.
Can I audit domains I don't own?
Yes. The bulk checker queries public DNS records — the same information anyone can look up with dig or nslookup. It's read-only and doesn't modify anything. Use it to research competitors, evaluate acquisition targets, or audit prospective clients.
Why does a domain show a low score but my email works fine?
Email can work without proper authentication — for now. But missing SPF/DKIM/DMARC means your deliverability is fragile. One policy change from Gmail or Outlook, and your email stops arriving. A low score is a warning, not necessarily a current outage.
How often should I run bulk audits?
Weekly for active client domains or production SaaS. Monthly for parked domains or personal projects. DNS changes happen — someone moves email providers, a certificate expires, a blacklist listing occurs — and you want to catch those changes early.