Free tool

Free Email Spam Checker

An email spam checker scans your subject line and body for the content signals spam filters weight: trigger words and phrases, all-caps and heavy punctuation, risky links, and formatting tricks. Paste an email below to get a spam score and a list of exactly what to change before you send.

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Understanding spam detection

Spam filters use complex algorithms to analyze email content, sender reputation, and user behavior. Understanding these systems helps you create content that reaches the inbox consistently.

Common triggers

Excessive capitalization

Using ALL CAPS or too many exclamation marks looks unprofessional.

Spam keywords

Terms like "free", "guarantee", "winner" trigger filters.

Poor formatting

Excessive punctuation, colors, or hidden text raises red flags.

Suspicious links

URL shorteners and IP addresses instead of domains.

Best practices

Write naturally

Use proper grammar, spelling, and conversational tone.

Provide value

Focus on helpful content rather than pure sales messaging.

Test regularly

Check content before sending to large lists or campaigns.

Build reputation

Consistent sending patterns and engagement improve deliverability.

What your spam score means

Every finding adds points. The total maps to a risk level, and the risk level is the number to act on: a new or cold-sending domain has no reputation to absorb content flags, so aim for the minimal band before every campaign.

Score	Risk level	What it means
0 to 4	Minimal	No meaningful triggers. Send as is.
5 to 14	Low	A few weak signals, usually one or two trigger words. Worth a quick edit.
15 to 29	Medium	Several triggers or one strong one (an all-caps subject, a spammy phrase). Fix before sending to a cold list.
30 to 49	High	Content reads like bulk mail to a filter. Rewrite the flagged lines.
50 and above	Critical	Multiple strong triggers stacked. Expect the spam folder at most providers.

What spam filters actually check

Content is one of three inputs. A perfect score here does not help if the other two are broken, which is why emails with clean copy still land in spam.

1. Content

Trigger words, urgency and money phrasing, all-caps, exclamation marks, image-only bodies, hidden text, link shorteners. This is what the checker above measures.

2. Authentication

SPF, DKIM and DMARC records on the sending domain. Gmail and Yahoo reject bulk mail without them. Verify yours with the SPF checker, DKIM checker and DMARC checker.

3. Reputation

Bounce rate, complaint rate, engagement and blacklist status of the domain and IP. Check your domain with the blacklist checker and read why emails go to spam for the reputation side.

How to lower your spam score

Rewrite the flagged phrases, don't just delete them. "Free", "guarantee" and "act now" score because of what they promise. Say what you actually offer in plain words.
Use sentence case in the subject. An all-caps subject is the single heaviest content flag in this checker.
One exclamation mark at most, and no rows of punctuation.
Link to your own domain. Replace shorteners and raw IP addresses with full URLs on a domain you control, ideally a custom tracking domain.
Keep text and images balanced. Image-only emails and hidden text are treated as evasion.
Re-run the check after editing. The score updates instantly, and the goal for cold outreach is the minimal band.

Spam checker vs spam test

A spam checker analyses the content of a draft before you send it. A spam test, also called an inbox placement test, sends a real email to seed mailboxes at Gmail, Outlook and other providers and reports whether it reached the inbox, promotions or spam.

Use this checker while writing. Before a campaign, run a placement test from the mailboxes that will actually send; InboxKit runs them on every mailbox it provisions, and the inbox placement testing guide explains how to read the results.

FAQ

Frequently asked questions

It scans the subject line and body against the content signals spam filters weight: known trigger words and phrases, all-caps and excessive punctuation, risky link patterns such as URL shorteners and raw IP addresses, and HTML formatting issues. Each finding adds to a score, and the tool lists every finding with the line it came from.

Lower is better. A score of 0 to 4 is minimal risk, 5 to 14 is low, 15 to 29 is medium, 30 to 49 is high, and 50 or more is critical. Cold email should aim for the minimal band, because a new domain has no reputation to offset content flags.

No. Content is one of three things filters weigh. The other two are authentication (SPF, DKIM and DMARC on your sending domain) and sender reputation (bounce rate, complaint rate, engagement, blacklists). A clean email from an unauthenticated or unwarmed domain still lands in spam.

A spam checker analyses the content of an email before you send it. A spam test, sometimes called an inbox placement test, sends a real email to seed mailboxes at Gmail, Outlook and other providers and reports where it landed. Use the checker while writing and a placement test before launching a campaign.

Yes. Paste the HTML source and the tool checks the visible text as well as the markup, including hidden text, image-only content and link structure.

Yes. There is no signup, no limit on checks, and nothing you paste is stored.