Subject line checker tool
Use the subject line checker to test your email subject line for spam words!
Here’s the problem with spammy email subject lines…
All email service providers have their respective systems for spam email detection. Their goal is to catch obvious bad actors who are looking to take advantage of unsuspecting email users with spammy, deceptive content to trick them or steal their data.
A spam word checker is a typical detection form. And your subject lines can trigger spam email detection automatically, relegating your emails to Spam.

How the email subject line checker works
Our free email subject line tool compares the text found in your subject line against a collection of well-known spam trigger words. Email service providers aren’t looking to block legitimate contact like yours, so they make no secret of what words or phrases can trigger their filters.
Our subject line/spam word checker highlights any known spam words and gives you a ratio of how many there are compared to safe-for-use words or phrases. Think of it like this: the more spam trigger words that are present, the more likely it is to impact email deliverabilityⓘ.
Examples of spam trigger words:
- ✔ Cheap
- ✔ Debt
- ✔ Eliminate debt
- ✔ Trial Offer
- ✔ Prize
- ✔ You won!
- ✔ Bonus
- ✔ Read this
- ✔ Prescription
- ✔ Invest

Best practices for creating safe and effective email subject lines
So – what are email marketing best practices when it comes to subject lines?
Keep these email marketing tips in mind.
Be direct
Be direct and descriptive
Everyone wants to include a little bit of clickbait in their subject lines. A bit of intrigue is acceptable (and practical!), but recipients should always have an understanding of what’s inside your email.
Readers should know from your email subject lines if they’re checking out an offer, an announcement, an update, or some other description that helps them understand how the email benefits them. Email service providers will also be checking to help them avoid spam emails.

Want to use our email deliverability tool to test your email?
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Warmup
Still hitting Spam after using our free email subject line tool? It could be your sender reputation.
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Inbox Placement Testing
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Email Server Testing
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Blacklist Monitoring
If you’re still hitting Spam with these email marketing tips, you need to make sure your domain isn’t on a blacklist/blocklist.
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DMARC monitoring
Securing your email and authenticating your identity will keep emails out of spam and improve email open rates.
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Free email verifier
Avoid bounces and risky emails. Check any email address with our free email validationⓘ and verification tool.
Find out if your contact’s address is valid and any other relevant information, including domain information and social data, when available.
Want to learn more? Check out our handy Email Deliverability Toolkit guide!
Avoid spam email with our free email subject line tool
Getting rid of spammy subject lines is easy. Click below to head back up and use our email subject line checker – and bookmark this page for frequent use!
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