Paste the draft
Drop the subject line and body you are about to send. We screen the copy for deceptive subjects, shouting formatting, image-only bodies, and stacked pressure phrases.
Pre-Send Spam Audit
Spam Content Checker That Scores What Filters Actually Read.
Audit your copy against the sender-signal checklist that modern filters actually read, then verify any address before you send. Free now.
Trusted by 500,000+ leading GTM teams of all sizes
How It Works
How the address check behind this page works
Content gets audited by hand, recipients by machine. Paste an address, let the nine-check engine score it, read the verdict.
Score the content
Eight content signals fire in sequence: subject honesty, formatting, image ratio, link patterns, pressure phrasing, HTML quality, attachment bait, and unsubscribe.
Read the verdict
Inbox-ready, risky, or likely spam, plus the exact signals that tripped and a 0-100 content score. Fix what is flagged, then verify the addresses before you send.
The hand-audit half
Eight content signals spam filters still score
Run your draft down this list before any send. Each one is a pattern filters learned from decades of complaint data, and each one is fixable in minutes.
Subject line
Deceptive subject lines
Fake “RE:” and “FWD:” prefixes, or a subject that promises something the body never delivers. CAN-SPAM makes misleading subjects illegal, and filters trained on complaint data treat them as the strongest content signal there is.
draft · subject
Formatting
Shouting formatting
ALL-CAPS subjects, stacked exclamation marks, currency symbols, and emoji walls. None of these carries a fatal penalty on its own, but together they reproduce the exact shape of the mail people already mark as junk every single day.
draft · formatting
Body
Image-heavy bodies
One large image and a dozen words of text is a classic spam silhouette. Filters cannot read pixels, so a body they cannot parse gets scored on suspicion. Keep a healthy text-to-image ratio and always ship real, readable copy in the message.
draft · body
Links
Suspicious link patterns
URL shorteners, many different domains in one message, and display text that does not match the underlying href. Phishing detection lives here, and it is unforgiving. Link to one or two domains you actually control. The email link checker audits every URL in the body.
draft · links
Copy
Stacked pressure phrases
“Act now”, “100% free”, “guaranteed”, “no obligation”. Each phrase is harmless in honest context, but clustered into a pitch-shaped paragraph they still pattern-match against decades of junk. Write like a person, not a late-night ad.
draft · copy
Markup
Sloppy or deceptive HTML
Broken tags, hidden white-on-white text, one-pixel fonts, and leftover template scaffolding. Filters parse your markup before any human ever sees it, and markup built to hide things from a reader is scored as exactly that. The email template checker digs deeper into rendering and broken markup.
draft · source
Attachments
Attachment bait
Unexpected .zip, .exe, or .html attachments in a first-touch email. Most gateways quarantine these shapes outright, no questions asked. If a prospect actually needs a file, link to it from a domain you own and control instead of attaching it.
draft · attachments
Structure
No unsubscribe or text part
HTML-only messages with no text/plain alternative, and bulk mail without a working unsubscribe link. Both are structural tells that legitimate senders never leave out, so filters read their absence loudly and score you down for it.
draft · headers
The honest version
What a spam checker measures
Not a trigger-word tally. The signals modern spam filters actually weight, and why a clean content score still keeps passing campaigns that die.
Type email spam content checker into Google and you are usually holding a finished draft and a deadline, wanting one number that says the campaign will land. The classic tools answer with a SpamAssassin-style score: every risky phrase, formatting quirk, and link pattern adds points, and anything over 5.0 gets junked by the older gateways still running those rules. That model is twenty years old and covers a shrinking slice of the inboxes you care about. Treat the score as a lint check on your prose, not a delivery guarantee, then spend the rest on the sender side.
How we stack up
Verifox vs other spam checkers
Content scanners score your words. Verifox verifies the recipient the filters judge you on and runs on credits that never expire.
★ The complete checkVerifox
Mail-Tester
GlockApps
Mail-Tester
GlockApps
Mail-Tester
GlockApps
Mail-Tester
GlockApps
Mail-Tester
GlockApps
Mail-Tester
GlockApps
Mail-Tester
GlockApps
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GlockApps
Mail-TesterN/A
GlockAppsMonthly
Why both halves matter
Clean copy still bounces off a dirty list
You can pass every content scanner on the internet and still hit the junk folder, because bounces and trap hits from a stale list outweigh your best subject line.
Built for the teams that ship outbound
Growth leads, marketers, and engineers running real campaigns on real lists, with a verified email on every byline.
90% lower bill, 0.4% bounces
We were paying ZeroBounce a four-figure monthly bill and still landing 3% bounces on cold campaigns. Switched the pipeline to Verifox, dropped to 0.4% bounces, and cut the bill by more than 90%.
Thomas G.GTM Lead, Stripe
Catch-all finally has a verdict
Other tools flag 30% of our B2B list as 'risky catch-all' and leave the call to us. Verifox returns a real verdict on those addresses, with a confidence score. We send more, we send safer.
Brittany K.GTM Lead, HubSpot
Reputation rebuilt in 6 weeks
We had a Gmail spam-folder problem after a bad list import. Verifox cleaned the list and the warmup ran on the same engine. Back in primary inbox in six weeks. One vendor, half the cost.
Dale M.GTM Lead, Slack
0.7% bounce on 50k
Ran a 50,000-address outbound list through Verifox before our quarterly campaign. Bounces landed at 0.7%, sender reputation didn't move, replies were up 22% over last quarter.
Erica K.GTM Lead, Discord
MCP in 10 minutes
Their MCP server let me wire email verification directly into our internal Claude agent in about ten minutes. Zero glue code. No other vendor in this space has thought about that workflow.
Greg L.GTM Lead, OpenAI
10k/min held under 400ms
Tested Verifox at 10,000 verifications per minute on a Tuesday morning. Latency held under 400ms median, no soft failures, no rate-limit walls. The vendor we benched throttled at 2,000/min.
Rini V.Product Manager, Vercel
Hygiene that doesn't break pipeline
Our SDRs were enriching from three tools and 14% of the emails were invalid before they hit the sequencer. Verifox sits in the pipeline now and the team stopped seeing 'undeliverable' replies the next week.
Jonathan A.GTM Lead, MongoDB
Bulk that actually ships
Bulk upload, sorted CSV back in twenty minutes, plug into our growth stack. The half-day list-hygiene project per cohort turned into something the marketing intern runs on autopilot.
Emma F.GTM Lead, Linear
Scores you can act on
Verifox returns a 0-100 confidence score per address, not just a label. We thresholded at 75 for the cold sequencer, 60 for nurture, and our deliverability team finally has a knob they can tune.
David H.GTM Lead, Snowflake
90% lower bill, 0.4% bounces
We were paying ZeroBounce a four-figure monthly bill and still landing 3% bounces on cold campaigns. Switched the pipeline to Verifox, dropped to 0.4% bounces, and cut the bill by more than 90%.
Thomas G.GTM Lead, Stripe
Reputation rebuilt in 6 weeks
We had a Gmail spam-folder problem after a bad list import. Verifox cleaned the list and the warmup ran on the same engine. Back in primary inbox in six weeks. One vendor, half the cost.
Dale M.GTM Lead, Slack
MCP in 10 minutes
Their MCP server let me wire email verification directly into our internal Claude agent in about ten minutes. Zero glue code. No other vendor in this space has thought about that workflow.
Greg L.GTM Lead, OpenAI
Hygiene that doesn't break pipeline
Our SDRs were enriching from three tools and 14% of the emails were invalid before they hit the sequencer. Verifox sits in the pipeline now and the team stopped seeing 'undeliverable' replies the next week.
Jonathan A.GTM Lead, MongoDB
Scores you can act on
Verifox returns a 0-100 confidence score per address, not just a label. We thresholded at 75 for the cold sequencer, 60 for nurture, and our deliverability team finally has a knob they can tune.
David H.GTM Lead, Snowflake
Catch-all finally has a verdict
Other tools flag 30% of our B2B list as 'risky catch-all' and leave the call to us. Verifox returns a real verdict on those addresses, with a confidence score. We send more, we send safer.
Brittany K.GTM Lead, HubSpot
0.7% bounce on 50k
Ran a 50,000-address outbound list through Verifox before our quarterly campaign. Bounces landed at 0.7%, sender reputation didn't move, replies were up 22% over last quarter.
Erica K.GTM Lead, Discord
10k/min held under 400ms
Tested Verifox at 10,000 verifications per minute on a Tuesday morning. Latency held under 400ms median, no soft failures, no rate-limit walls. The vendor we benched throttled at 2,000/min.
Rini V.Product Manager, Vercel
Bulk that actually ships
Bulk upload, sorted CSV back in twenty minutes, plug into our growth stack. The half-day list-hygiene project per cohort turned into something the marketing intern runs on autopilot.
Emma F.GTM Lead, Linear
90% lower bill, 0.4% bounces
We were paying ZeroBounce a four-figure monthly bill and still landing 3% bounces on cold campaigns. Switched the pipeline to Verifox, dropped to 0.4% bounces, and cut the bill by more than 90%.
Thomas G.GTM Lead, Stripe
0.7% bounce on 50k
Ran a 50,000-address outbound list through Verifox before our quarterly campaign. Bounces landed at 0.7%, sender reputation didn't move, replies were up 22% over last quarter.
Erica K.GTM Lead, Discord
Hygiene that doesn't break pipeline
Our SDRs were enriching from three tools and 14% of the emails were invalid before they hit the sequencer. Verifox sits in the pipeline now and the team stopped seeing 'undeliverable' replies the next week.
Jonathan A.GTM Lead, MongoDB
Catch-all finally has a verdict
Other tools flag 30% of our B2B list as 'risky catch-all' and leave the call to us. Verifox returns a real verdict on those addresses, with a confidence score. We send more, we send safer.
Brittany K.GTM Lead, HubSpot
MCP in 10 minutes
Their MCP server let me wire email verification directly into our internal Claude agent in about ten minutes. Zero glue code. No other vendor in this space has thought about that workflow.
Greg L.GTM Lead, OpenAI
Bulk that actually ships
Bulk upload, sorted CSV back in twenty minutes, plug into our growth stack. The half-day list-hygiene project per cohort turned into something the marketing intern runs on autopilot.
Emma F.GTM Lead, Linear
Reputation rebuilt in 6 weeks
We had a Gmail spam-folder problem after a bad list import. Verifox cleaned the list and the warmup ran on the same engine. Back in primary inbox in six weeks. One vendor, half the cost.
Dale M.GTM Lead, Slack
10k/min held under 400ms
Tested Verifox at 10,000 verifications per minute on a Tuesday morning. Latency held under 400ms median, no soft failures, no rate-limit walls. The vendor we benched throttled at 2,000/min.
Rini V.Product Manager, Vercel
Scores you can act on
Verifox returns a 0-100 confidence score per address, not just a label. We thresholded at 75 for the cold sequencer, 60 for nurture, and our deliverability team finally has a knob they can tune.
David H.GTM Lead, Snowflake
Enterprise-grade security and scale
Every layer of the stack carries a third-party attestation, so you can ship into regulated industries without rebuilding your compliance posture.
SOC 2 Type II
Independently audited to the SOC 2 Type II standard.
GDPR
Built for the EU with full GDPR data-subject rights.
CCPA
California opt-out, do-not-sell, plus DSAR handling.
ISO 27001
Information security held to the ISO 27001 standard.
ISO 42001
AI governance aligned to the new ISO 42001 standard.
Common questions
Spam content checks, answered
What teams ask before a send: which content rules still apply, what a safe spam score looks like, and why the list usually matters more than the words. Straight answers, real numbers.
Does this page scan my subject line and body copy?
No, and we will not pretend otherwise. Verifox does not read your prose. The eight content signals on this page are a hand-audit checklist drawn from how filters actually score messages, and the widget up top checks the addresses you plan to send to.
That split is deliberate: content problems are fixable in your draft in ten minutes, while list problems need machinery. If your question is whether a specific address is risky, the address-level spam check answers it directly.
Do spam trigger words still get emails blocked in 2026?
Rarely on their own. Gmail and Microsoft moved to machine-learning filters that read context, so “free” in a genuine offer is fine while a stack of pressure phrases in a pitch-shaped sentence still pattern-matches badly.
The exception is older corporate gateways running SpamAssassin-style rules, which do assign per-phrase points. If you sell into enterprises, keep the phrase clusters out of cold email and watch your overall email health instead of any single word.
What spam score is considered safe?
For SpamAssassin-style scoring, the default junk threshold is 5.0, and careful senders aim under 3. Treat that number as linting, not a guarantee: Gmail and Microsoft publish no score at all and weigh sender history far more than content.
A message that scores 0 can still junk if the sending domain has a poor reputation or the list is full of dead addresses. Score the content once, then spend your remaining time on the sender side.
Why do my emails go to spam even when the content is clean?
Because content is a minority input. The usual culprits are missing or misaligned authentication, a domain or IP on a blocklist, and a stale list driving bounces and complaints.
Work through them in order: run an SPF, DKIM, and DMARC check on your domain, scan it with the domain spam checker, confirm nothing is listed via the email blacklist check, then clean the list itself. Most “mystery” junking is one of those four.
How do I test an email for spam before a big campaign?
A reliable pre-send routine has four steps. Audit the draft against the eight content signals above. Check the rendering and links with the email template checker. Run a deliverability test to seed inboxes across providers. Then verify every recipient so bounces never enter the equation.
The whole routine takes under an hour and removes the guesswork that a single content score never could.
What does the checker widget on this page actually verify?
Nine address-level checks run in parallel: syntax against RFC 5321 and 5322, domain existence and MX records, a live SMTP handshake with a mailbox ping, disposable-domain match, role-address detection, catch-all detection, an AI-confidence pass on catch-alls, domain age, and SPF, DKIM, and DMARC authentication.
The catch-all resolution matters most: 20 to 40% of B2B lists fail at catch-all domains, the check most free tools skip.
Is it actually free, and what do I get on signup?
You can run 4 verifications per day from this page with no account at all. Create a free account and you get 1,000 credits immediately, or 2,500 if you sign up with a work address. No card either way.
Past that, credits are pay-as-you-go and never expire, with volume pricing shown for your region.
Can I clean an entire list before I hit send?
Yes, and you should: it is the highest-leverage spam fix available. Upload a CSV or call the API and bulk verification runs at roughly 10,000 emails per minute on the standard tier, with a per-address verdict and confidence score back.
Single checks return in about 380 ms median. The API docs cover both shapes, and the SLA runs 99.9% on Starter up to 99.99% on an annual Volume contract.
Do you store the emails I check here?
No. Every address is processed in memory and discarded the moment the verdict returns. Nothing is logged, retained, or sold, which matters when the list you are cleaning is your customer base.
Verifox is SOC 2 Type II compliant, and the privacy policy spells out exactly what we touch. Live uptime is public at status.verifox.ai.
Can my app or AI agent run these checks automatically?
Yes. The REST API drops the same 9-check engine into signup forms, CRMs, and sequencers, and HubSpot, Salesforce, Zapier, Klaviyo, Mailchimp, and Brevo connect out of the box.
For agents, Verifox ships a native MCP server, so Claude, Cursor, or a custom LLM app can verify recipients before a send without glue code. Point the agent at the MCP URL and the tools are wired.