Email Deliverability Checker and Tester: Test Your Cold Email Spam Score
An email deliverability checker tells you whether a message will reach the inbox before you send it to a real list. Paste your cold email below and it scores the copy for spam trigger words, risky formatting and the structural signals mailbox filters weigh, then shows you exactly what to change.
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Spam & deliverability checker
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No obvious spam triggers found. Sender reputation and authentication still matter most, so keep your domain warmed up.
Free tool. Nothing you type is stored or sent anywhere.
What this email deliverability checker tests
Spam trigger words
Flags high-risk phrases like "100% free," "act now," "guarantee," and "make money" that classifiers weight against you, plus salesy filler that piles up when you overuse it.
Risky formatting
Catches the structural patterns that matter more than any single word: ALL-CAPS subject lines, stacked exclamation marks, too many links, and money amounts in a first touch.
Reply-rate hygiene
Checks length, whether you actually asked a question, and subject-line size, because the same things that please filters also get more humans to reply.
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How to test email deliverability in three steps
Paste your draft
Drop your subject line and body into the checker above. It analyzes as you type and never leaves your browser.
Read the flags
Each issue is ranked high or low risk with a plain-English fix. Work the red items first, then trim the salesy words.
Send and warm up
Clean copy is step one. Authenticate your domain, warm the inbox, and verify your list so a good email actually reaches the inbox.
Why cold emails land in spam
Most deliverability problems are technical before they are about wording. Mailbox providers score the sender first: is the domain authenticated with SPF, DKIM, and DMARC, is it warmed up, and is it sending to real addresses that do not bounce. Since 2024, Gmail and Yahoo require DMARC for anyone sending at volume.
Content is a real but secondary signal. A clean, established domain can use the word "free" once and still land in the inbox. A brand-new domain blasting an all-caps subject with three links will not. This checker focuses on the content and formatting half of the equation, the part you control inside the email itself.
Spam trigger words still worth avoiding
Single words rarely sink a message on their own anymore, but clusters of them do. The riskiest are money and urgency phrases: "financial freedom," "make money fast," "risk free," "act now," "limited time," and "guaranteed." We keep a fuller list, with safer rewrites, in our rundown of cold email spam words. Caps-locked "FREE" in a subject line landed in spam 82% of the time in one 2026 deliverability audit.
The fix is not a thesaurus. Write the way you would to a colleague: specific, lower-case, one clear ask, no hype. If a phrase sounds like a billboard, the filter agrees with you. The same instinct applies to your opener, which is why a researched cold email first line beats a hyped one.
What matters more than words in 2026
Modern filters are multi-signal systems, and the heaviest inputs are structural and reputational, not lexical. The priority order for cold email deliverability looks like this: a pre-warmed inbox, clean DNS and authentication, a verified list with low bounce rate, sane sending volume, then formatting, and only last the specific words you chose.
That is why the checker grades formatting hard: caps, exclamation marks, link count, message length, and whether you asked a question. Get those right and word choice mostly takes care of itself. The underlying causes are laid out in our guide to why cold emails go to spam.
How do you test email deliverability before you send?
Test email deliverability in three passes. First, run the copy through the spam checker above to catch trigger words and risky formatting. Second, confirm your sending domain has SPF, DKIM, and DMARC set correctly, since a failing record sends most cold email straight to spam. Third, send a seed test to a few real inboxes across Gmail, Outlook, and Yahoo and check where each one lands. Do all three before a campaign, not after your reply rate drops.
A spam test is only one of the three jobs this software category does, alongside reputation monitoring and warm-up. We broke down which email deliverability tools are worth paying for, and which free checks to run before you pay for any of them.
What is a good email deliverability rate for cold email?
A healthy cold email program lands 90 percent or more of messages in the inbox, keeps its spam-complaint rate under 0.10 percent, and holds bounces under about 3 percent. Google and Yahoo will throttle or block senders who cross a 0.30 percent complaint rate, so treat that as a hard ceiling. If your inbox placement is below 90 percent, the fix is usually authentication, warmup, and list quality, not the words in one email. Pair this checker with proper email warmup and a clean list, and keep an eye on your cold email bounce rate as volume grows.
How do I check my email deliverability?
Check email deliverability in two passes. First run the message itself through a content check like the one above: it scores subject line, body copy, link count and formatting the way a filter would. Second, confirm the sending domain publishes SPF, DKIM and DMARC, because a clean draft from an unauthenticated domain still lands in spam.
Content and authentication fail in different ways, and they fail independently. A perfectly authenticated domain will still get filtered if every message opens with "act now" and carries four tracked links. A beautifully written email from a domain with no DMARC record gets treated as unverified mail from a stranger. You need both to pass, which is why the checker above flags copy problems and this page walks the record setup separately.
What is an inbox placement test?
An inbox placement test sends a seed message to a panel of real mailboxes across Gmail, Outlook, Yahoo and corporate servers, then reports which folder it landed in at each provider. It measures where mail actually arrives, rather than predicting it from the content, so it catches reputation problems a copy checker cannot see.
Placement tests are the right tool once you have already cleaned the copy and set up authentication and the mail is still not getting replies. They cost money because every test burns a seed list. The paid options and what they charge are compared below, and a full breakdown lives on our email deliverability tools page.
What does an email deliverability tester actually measure?
A deliverability tester measures one of three different things depending on the tool. Content testers score the draft for spam signals. Placement testers report which folder seed mail reached at each provider. Reputation monitors track whether your sending IP or domain appears on blocklists. Most buyers need the first, then the third.
| Test type | What it answers | Typical cost |
|---|---|---|
| Content and spam score | Does this draft read like bulk mail | Included here at no charge |
| Inbox placement | Which folder did it reach at Gmail and Outlook | Roughly $0.07 to $1.05 per test |
| Domain and IP reputation | Am I on a blocklist right now | Bundled into monitoring plans |
Per-test costs are our arithmetic from the published plan prices and credit counts, read directly from each vendor. They move, so treat them as an order of magnitude rather than a quote.
What is a good deliverability score for cold email?
For cold email, aim for inbox placement above 90 percent at Gmail and Outlook and a bounce rate under 3 percent. Below 85 percent placement, something structural is wrong: authentication, domain age, list quality or send volume ramped too fast. A content spam score is a pass or fail gate, not a number to optimize.
Chasing a perfect content score past the point of passing is wasted effort. Once the draft clears the obvious traps, the remaining variance comes from who you are sending to and how consistently you send. Sending relevant, individually written mail to a list that actually wants to hear from you moves placement further than any word swap, which is why AI email personalization and list hygiene matter more than a thesaurus.
Who uses a cold email spam checker
Sales and SDR teams
Quality-check sequence steps before they go to thousands of prospects, so one bad template does not burn the whole domain's reputation.
Agencies and consultants
Vet client outreach copy fast and prove you are protecting deliverability, not just sending volume.
Founders doing outbound
Sanity-check a first cold email when you do not have a deliverability expert on staff yet.
Recruiters and BD reps
Keep candidate and partnership outreach out of the junk folder where it never gets seen.
Email deliverability checker FAQ
An email spam checker scores a message the way a mailbox filter would, flagging trigger words, risky formatting and structural patterns that look like bulk mail. It tells you whether the copy itself is working against you before you send it to a real prospect.
What a copy checker cannot see is your sender reputation, which decides most placement outcomes. Use it alongside a live inbox placement test rather than instead of one.
Run the copy through a spam checker first to catch trigger words and formatting problems, then send seed emails to real accounts on Gmail, Outlook and Yahoo to see where they actually land. The copy scan takes seconds; the placement test tells you what reputation is doing.
Check your domain and IP against the major blocklists at the same time. Those three checks together cover both halves of the problem.
Aim for a score with no high-risk flags and at most one or two low-risk ones. On the sender side, the number that matters more is your Gmail spam complaint rate: Google's guidelines say stay under 0.30 percent and aim below 0.10 percent.
A perfect copy score with a 0.5 percent complaint rate will still land in spam, which is why the sender checks come first.
The highest-risk words are money and urgency phrases: free money, 100% free, risk free, guarantee, act now, limited time, make money, financial freedom, and winner. In modern filters a single word rarely triggers spam on its own. It is the combination of several salesy words plus poor sender reputation or pushy formatting that pushes a message to the junk folder.
Fix the technical foundation first: set up SPF, DKIM, and DMARC, warm up the inbox for two to three weeks, and verify your list so you are not bouncing on invalid addresses. Then keep the email plain text, under about 125 words, with one link or none, no all-caps, and a single clear question. Authentication and warm-up do more for deliverability than any wording change.
No. A targeted, relevant cold email sent to a business contact with a genuine reason to reach out, a real sender identity, and a working unsubscribe option is legitimate outreach under US CAN-SPAM rules. It becomes spam when it is sent in bulk to unverified lists, hides who sent it, or uses deceptive subject lines. Relevance and honesty are what separate cold email from spam.
Run the copy through a spam checker like the one above to catch trigger words and risky formatting, then send a few live test emails to seed accounts on Gmail, Outlook, and Yahoo to see where they land. Also check your sending domain and IP against blocklists at mxtoolbox.com. The combination of a content scan plus real inbox placement tests gives you the clearest picture.
They matter, but less than people think. Sender reputation, authentication, and list quality carry far more weight than any single word. Trigger words act as a low to medium signal that can tip a borderline message into spam when the sender reputation is already shaky. On a clean, warmed-up domain, an occasional word like free is usually fine. Treat word choice as polish, not the main lever.
One link at most in a first cold email, and zero is often better. Three or more links is one of the strongest content-based spam signals because it mirrors promotional blasts. Save the calendar link, case study, and website for a reply or a later follow-up once the prospect has engaged. A first email should earn a conversation, not route the reader somewhere.
Run your copy through a spam checker for trigger words, verify SPF, DKIM, and DMARC are passing on your sending domain, then send a seed test to real Gmail, Outlook, and Yahoo inboxes to see where it lands. Doing all three before you launch catches the issues that a single tool would miss.
Aim for inbox placement of 90 percent or higher, a spam-complaint rate under 0.10 percent, and a bounce rate under about 3 percent. Mailbox providers throttle senders who pass a 0.30 percent complaint rate, so keep well clear of it. Low placement is almost always an authentication, warmup, or list-quality problem rather than a wording problem.
Yes, the checker on this page runs in your browser at no charge and nothing you paste is stored or transmitted. It is the content half of deliverability. Fixing what it finds is only useful if the mail then goes out from an authenticated domain at a sane volume, which is what a ColdMailer plan handles.
No. A checker removes the content reasons a filter would reject you, which is the part you fully control. Placement also depends on domain reputation, authentication records, send volume, list quality and recipient engagement. Passing the check makes inbox placement likely, not certain.
Test every new template before it goes to a list, and re-test whenever reply rates drop or you add a sending domain. Templates that passed six months ago can start failing as filters change and as the phrase gets overused across the market.
Pass the deliverability check, then send from your own domain
Clean copy only pays off if the send behind it is clean too. ColdMailer writes a separate message for every prospect and sends it through your own SMTP, so your domain builds its own reputation instead of sharing a pool.
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