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An email spam checker scores the part you control: the words, the subject line and the format. Gmail and Outlook don't publish banned-word lists, and they weigh sender reputation most, so treat the grade as a pre-flight check, not a guarantee.
How the score works
Every email starts at 100. Each flagged word or format issue takes off a few points, and the breakdown shows exactly how many. The score is a strong starting point: we recommend avoiding what’s flagged, but it isn’t a delivery promise. Sender setup, your list and your provider’s rules matter too.
Subject line score
The subject gets its own small score and a length meter, so this is also a subject line tester: leave the body empty to check a subject on its own. A flagged word costs twice as much in the subject as in the body. That matches SpamAssassin, the one major spam filter whose rules are public: it reads the subject as the first line of the email and then runs subject-only checks on top.
Merge fields such as {{first_name}} are skipped, so personalized subjects score on their real words.
The flagged-word categories
Account and security scares
"Verify your account", "account suspended", "final notice". Filters and readers both distrust them.
Hype and pressure
"100% free", "act now", "risk-free", "winner", "$$$". Each adds weight; several together tip the balance.
How it looks
ALL CAPS, "!!!" in the subject, too many links, no unsubscribe line on marketing mail.
How to fix a failing email
Fix the red words first
Red means likely blocked. Swap them using the suggestions, then re-send to re-check.
Calm the subject line
30–60 characters, no ALL CAPS, one punctuation mark at most.
Cut links to three or fewer
Use your own domain, and describe where each link goes.
Add an unsubscribe line
Required for marketing email, and it lowers complaints.
Words to avoid in subject lines, and what to use instead
One flagged word rarely decides where an email lands, but in a subject of six or seven words it stands out to filters and readers alike. These are the swaps "Clean it up" makes; they keep the meaning.
Some phrases have no safe swap because they describe what the business sells, such as "no credit check" or "cash advance". The checker flags them and leaves the wording to you: a vaguer word doesn't change the rules that apply. The full lists are in our spam trigger words guide.
Subject lines before and after
Subject scores from the checker above, checked on October 9, 2026.
The "after" versions are calmer and more specific: they say what the email is about, which is also what gets them opened.
Why debt, loan and cash wording gets flagged
Lending scams lean on the same words honest finance businesses use, so filters treat debt, loan, cash advance, credit repair and guaranteed approval as high-risk. In email they cost points; in text messages carriers often block them outright. See the text message checker for the SMS rules.
Swaps help a legitimate email read less like spam. They don't change what you're offering, so describe the offer plainly and leave out promises like "guaranteed approval" unless they're true.
Did you know these everyday words are on the lists?
Plenty of normal business words show up on spam-word lists: real estate, quote, offer, deal, trial, sample, bonus, cash, payment, debt. Using one of them once in an email is usually fine. Repeating it, or stacking several in one email, is what tips a filter. The checker underlines each one and tells you when a word appears more than once.
Honest ways around it
Say it once, then vary it
"Real estate" once, then "home", "listing" or "property". Same meaning, less repetition.
Watch your business name
If your company name contains a flagged word, it shows up in every email you send. A short form of your name in the subject line and greeting keeps the count down.
Keep the offer honest
Rewording helps a legitimate email read less like spam. It isn't a way to hide what you're offering, so describe the offer plainly.
Frequently asked questions
Can I email or text customers about alcohol, vape or firearms?
Email platforms set their own acceptable-use rules, so check yours. For texting: Alcohol can be texted to confirmed adults when your number is registered for it and sign-ups are age-checked with a date of birth. Tobacco, vape and firearms are allowed by some carriers with age checks, but many providers, Twilio included, restrict or don’t carry them, so check yours. Gambling promotions aren’t carried on US business texting; a casino or venue can still text non-gambling updates.
Should I use a short version of my business name?
A short form your customers recognize keeps texts brief and avoids repeating a flagged word. It doesn’t change what your business does, so provider rules about your type of business still apply.
Does the checker open my links?
No. It reads each link and flags malformed links, bare IP addresses, look-alike domains, public shorteners and link text that shows a different site. Every link finding is labelled "Destination not checked".
How do I check if my email will go to spam?
Run it through a spam word checker for wording and format, then send a test to Gmail and Outlook accounts you own. Sender reputation and authentication (SPF, DKIM, DMARC) matter most.
What words trigger spam filters?
Pressure and hype phrases like "act now", "100% free" and "winner", phishing phrases like "verify your account", and high-risk finance terms like "debt relief". See the full spam trigger words list.
How long should an email subject line be?
30 to 60 characters reads well on desktop and phone. Avoid ALL CAPS and repeated punctuation.
What is a subject line tester?
A tool that scores an email subject line before you send it. This checker does it as part of the email check: it flags spam words, ALL CAPS, "!!!", the length and hidden characters (and a fake "Re:" in HTML mode), and suggests safer swaps.
Can a subject line send an email to spam?
It can add to the risk. Filters weigh the sender's reputation and setup most, but pressure words, ALL CAPS and "!!!" in the subject add up with everything else.
Is "free" a spam word in a subject line?
On its own it's mild. "100% free" and "free gift" are stronger signals, and repeating "free" adds up. "Complimentary" is a safe swap that keeps the meaning.
Should I start a subject line with "Re:" or "Fwd:"?
Not on a first email. It pretends to be a reply, which readers and filters distrust, and in the US a commercial subject line must not mislead about what the email contains (FTC, CAN-SPAM).
What is a spam score?
A quick estimate of how likely your wording is to look like spam. This checker scores your email from 0 to 100: 85 to 100 looks good, 70 to 84 is worth a review, and 0 to 69 needs work. It checks wording and format only; your sender setup, your list and your sending history matter too.
Can I check my email for spam words?
Yes. This is also a spam word checker: paste your email and it underlines spam trigger words, rates each one and suggests a safer swap. It checks the subject line, links, ALL CAPS and the unsubscribe line as well.
Is this spam checker private?
Yes. It runs entirely in your browser. Nothing you paste is sent or stored.
Does Gmail have a list of banned words?
No. Gmail and Microsoft don't publish one. Their filters weigh sender reputation and setup most; wording is the part you control.
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