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Free tool

Cold email spam checker

Paste the subject and body. You get a 0-100 risk score, the words and patterns that send your email to spam or kill the reply, and concrete replacements. Works in English and Polish.

The tool checks two things at once. First, the words and patterns that Gmail and Microsoft filters react to - promises, pressure, money, phishing-style phrasing. Second, what people react to - corporate filler, empty follow-ups, exclamation marks and capitals that make the reader delete after the first line.

The word lists come from our own campaigns. Every phrase on the list was either caught by a filter in practice or lowered reply rates enough that we stopped using it. It is not a generic list copied from the internet.

How the score works

Every hit carries a weight based on how strongly it triggers filters: phishing patterns and time pressure weigh most, money and promotion words weigh medium, filler and risky single words weigh least. On top of that we check structure: subject length, body length, number of links, exclamation marks, words in capitals, fake Re: subjects.

Below 15 the email passes filters and reads like a person. Between 15 and 34, fix the flagged parts before sending at volume. Above 35 the email should not go out in this form because it damages the domain for every send that follows.

What this tool does not check

Copy is one third of deliverability. The rest is infrastructure and the list. The tool cannot see whether your domain has correct SPF, DKIM and DMARC, whether the mailbox is warmed up, or whether the addresses on the list are verified. Any of those three can send a perfect email to spam.

  • Check your DNS setup with our SPF, DKIM and DMARC checker.
  • Warm-up and daily limits are covered in the article on managing mailboxes at scale.

The three mistakes we see most often

First, a subject line with a promise. Free, guaranteed, special offer in the subject is the shortest route to spam and the shortest route to a human deleting the email.

Second, a follow-up with nothing new. Bumping this, just checking in, circling back. Filters do not punish it, readers do. Every next email in a sequence has to add a new reason to reply.

Third, length. The first email should be 50-120 words with one question. Anything over 180 words reads like an offer, and nobody reads offers in their inbox.

Frequently asked questions

Does a score of 0 guarantee the inbox?
No. A score of 0 means the copy carries no known spam signals. Deliverability also depends on the domain, mailbox reputation, warm-up and list quality. Good copy on a burned domain still lands in spam.
Does it work in Polish?
Yes. It has separate lists for Polish and English, including the Polish corporate phrases that lower reply rates.
Do you store my emails?
No. The text is analysed on the fly and never stored. You only leave an address if you want to unlock the full list of findings.
Why is the full list behind an email?
Because the full report with replacements is our work from a few hundred campaigns. The score and the top three findings are free with no conditions; the rest is in exchange for a work email, to which we send one tactic every two weeks.
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Albert Zuszman
Albert ZuszmanFounder, Scaling Labs

Albert Zuszman runs Scaling Labs, a B2B prospecting agency based in Warsaw. He has spent years building cold email and cold calling campaigns for B2B companies, PE funds and teams entering the Polish market. He writes about what works in real projects, with campaign numbers.