How to Check Your Email Deliverability Before Sending a Cold Campaign

Most cold email campaigns fail before a single email lands in an inbox. The domain has broken DNS records. The IP is already blacklisted. The content triggers spam filters built for patterns from 2022. You only find out when reply rates sit at zero and your domain reputation takes a hit that takes weeks to recover from.

The fix is a structured pre-send deliverability audit. This guide gives you the exact checklist — tools, tests, and thresholds — to run before you fire a single message from a cold campaign.

Why Pre-Send Testing Matters

Inbox placement is not binary. Emails don't simply arrive or bounce — they land in Primary, Promotions, Spam, or get silently dropped entirely. Google and Microsoft score every inbound message in milliseconds using hundreds of signals: domain age, sending history, DNS record alignment, content patterns, and recipient engagement.

A domain with a 90-day sending history and a clean SPF/DKIM/DMARC setup sending plain-text emails will land in Primary roughly 85–92% of the time. A brand-new domain sending HTML-heavy emails with a missing DMARC record might get 20–30% Primary placement — or worse.

Pre-send testing lets you catch these problems in a controlled environment before your reputation is on the line. Spend 30 minutes on these checks and you'll avoid the most common deliverability disasters.

Step 1: Verify Your DNS Records Are Correct

DNS misconfiguration is the single most common deliverability killer. You need three records set correctly: SPF, DKIM, and DMARC. For a full walkthrough of how to configure each one, see our guide on setting up cold email infrastructure.

Check SPF

Your SPF record tells receiving mail servers which IP addresses are authorized to send email from your domain. Use MXToolbox (mxtoolbox.com/spf.aspx) or dmarcian SPF Surveyor to verify your SPF record looks up correctly and doesn't exceed the 10 DNS lookup limit.

A correct Google Workspace SPF record looks like this:

v=spf1 include:_spf.google.com ~all

The ~all softfail is standard for cold email. Using -all (hardfail) is more strict and can cause legitimate emails to be rejected if your setup has any gaps.

Check DKIM

DKIM adds a cryptographic signature to each email. Google Workspace automatically sets up DKIM — but you need to activate it in the Admin Console. Navigate to Apps > Google Workspace > Gmail > Authenticate email, then generate and publish your DKIM key.

After publishing, use MXToolbox DKIM Lookup with your selector (usually google) and domain to verify the public key is resolving. A missing DKIM record is an immediate deliverability penalty.

Check DMARC

DMARC tells receiving servers what to do when an email fails SPF or DKIM alignment. Start with a monitoring-only policy: p=none. This doesn't reject anything but tells servers you have a DMARC policy in place — which itself improves inbox placement.

v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.com

Use MXToolbox DMARC Lookup to verify the record resolves. For a detailed walkthrough of the full DNS setup, read our email domain warm-up and DNS configuration guide.

Step 2: Check Domain and IP Blacklists

Before sending anything, check whether your sending domain or IP address appears on major spam blacklists. A single listing on Spamhaus can tank your deliverability to near zero for Gmail and Outlook.

Use these tools:

MXToolbox Blacklist Check — checks 100+ blacklists simultaneously. Aim for zero listings.
Spamhaus Domain/IP Lookup — the most authoritative list. Being on SBL, XBL, or DBL is critical.
MultiRBL.valli.org — another multi-list checker for IP reputation.

If your IP is on a blacklist, check whether your ESP (Google, Microsoft) rotates sending IPs. If you're using a dedicated IP through a tool like Mailgun, you'll need to request IP removal through each blacklist's individual delisting process.

Step 3: Run an Inbox Placement Test

Inbox placement tests send a real email to seed accounts maintained by the testing service across different email providers and report where the message landed: Primary, Promotions, Spam, or Missing.

The best tools for this are:

GlockApps — the gold standard for inbox placement testing. Tests across Gmail, Outlook, Yahoo, Apple Mail, and more. Shows a placement percentage per provider. Target 80%+ Primary in Gmail and Outlook.
Mailreach — combines placement testing with reputation monitoring and warm-up. Good for ongoing monitoring.
Lemwarm (from Lemlist) — focused on warm-up but includes placement metrics. Useful if you're already in the Lemlist ecosystem.

Run your test with the exact email content you plan to send — subject line, body copy, signature, and any links included. The placement result will change depending on your content.

Step 4: Check Your Spam Score

Spam scoring tools analyze your email content against known spam filter rules and give you a numeric score. The most widely used scoring engine is SpamAssassin, which many ESPs use internally.

Use Mail-tester.com — send your campaign email to a unique address it generates, then check your score. A score of 9/10 or higher means your email is unlikely to trigger content-based filters. Scores below 7/10 need attention before sending.

Common score penalties include:

Using spam trigger words: "free," "guaranteed," "act now," "click here"
All-caps subject lines or body sections
Excessive exclamation marks
Missing plain-text version (HTML emails only)
Broken or redirecting links
Tracking pixel mismatches

Step 5: Test Your Links and Tracking Domains

Every link in your email is checked by spam filters before delivery. If your tracking domain (used for open and click tracking) is on a blacklist, or if your links redirect through a suspicious intermediary, it will tank your placement.

Best practices for links in cold email:

Use your own custom tracking domain, not the ESP's default domain (shared tracking domains are often abused)
Set up your custom tracking domain as a CNAME record pointing to your ESP
Limit links to 1–2 per email maximum
Avoid URL shorteners (bit.ly, tinyurl) — these are heavily penalized
Check all destination URLs against Google Safe Browsing and Spamhaus DBL

Tools like IsItPhishing.ai and VirusTotal URL Scanner can verify your destination URLs aren't flagged.

Step 6: Verify Domain Age and Warm-Up Status

New domains need a warm-up period before they can send cold email reliably. Google and Microsoft trust sending history — a domain that has been consistently sending and receiving legitimate email for 60–90 days will get much better placement than a domain registered last week.

Warm-up benchmarks for cold email readiness:

Week 1–2: 5–10 emails per day (warm-up tool handles this)
Week 3–4: 20–30 emails per day
Week 5–8: 40–60 emails per day
Week 9+: 80–100 emails per day max for cold outreach

Check your domain's age at WHOIS Lookup tools. If the domain is under 30 days old, don't start cold campaigns yet. See our full cold email deliverability checklist for the complete warm-up timeline.

Step 7: Check Google Postmaster Tools

If you're sending through Gmail or Google Workspace, Google Postmaster Tools(postmaster.google.com) gives you direct visibility into your domain's sending reputation in Google's eyes.

Key metrics to monitor:

Domain Reputation: Should be "High" or "Medium." "Low" means serious deliverability problems.
Spam Rate: Should stay below 0.10%. Above 0.30% triggers automatic throttling.
Authentication: Shows SPF, DKIM, and DMARC pass rates. Target 100%.
Encryption: Should show 100% TLS encryption for outbound messages.

You need to verify domain ownership in Postmaster Tools before data becomes available. Set this up for every cold email domain you operate.

The Pre-Send Checklist Summary

Run through this list before every new campaign:

SPF record set and validating (MXToolbox)
DKIM activated and key resolving
DMARC record present (p=none minimum)
Domain not on any major blacklist
Inbox placement test 80%+ Primary in Gmail/Outlook (GlockApps)
Mail-tester.com score 9/10 or higher
Custom tracking domain set up (not ESP default)
All links clean (no URL shorteners, no blacklisted domains)
Domain 60+ days old or warm-up completed
Google Postmaster domain reputation "High" or "Medium"

This 30-minute audit will catch 90% of deliverability problems before they cost you your sending reputation. Build this into your campaign launch process as a non-negotiable gate — don't skip it even when you're in a rush to launch.

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