Most cold email does not fail because the offer is wrong. It fails because it never gets read: the filter catches it, or the subject line looks like every other pitch in the inbox, and it is gone. The free Cold Email Spam Checker scores a subject line and body against the rules filters actually use and lists the specific issues with fixes. This guide explains what it checks, what the score means and how to rewrite around each flag.
Step 1: Paste the subject and the body
Paste the email exactly as it would send, including the signature and any unsubscribe line, because those are scored too. Add your name and email and run the check. You get a score, a risk level and an itemised list of what was found.
What the checker looks for
All caps and punctuation abuse
A subject line in CAPITALS, or three exclamation marks, or "FREE!!!" is the oldest spam signal there is. Filters still weight it, and so do humans. Write subject lines the way you would write a text to a colleague.
Spam trigger words
Words and phrases that appear far more often in spam than in legitimate mail: "act now", "guarantee", "no obligation", "risk-free", "limited time", "100%", "earn money". A single one is survivable. Several in one email is a pattern. The checker lists each one it finds so you can swap it for plainer language.
Link density and shorteners
Spam contains lots of links relative to text, and it hides them behind shorteners. A cold email should have at most one or two links, written out in full on your own domain. Never use bit.ly or similar in cold email; filters treat shortened links as an attempt to hide the destination.
Personalisation and signature
Legitimate email is addressed to a person and signed by a person. The checker looks for a greeting, a name, and a real signature with a company and a way to reach you. An email with none of these reads as a broadcast to a filter and to a reader.
Opt-out and compliance
Commercial email in the US needs a working way to opt out and a physical address under CAN-SPAM. Beyond the legal requirement, the presence of an unsubscribe line is a trust signal to filters because spammers omit it.
Sending volume and domain health
The copy is only part of deliverability. The checker also flags the practices that get domains blocked: sending from a brand-new domain at volume, no warm-up, no SPF or DKIM, images with no text. If your domain reputation is damaged, no amount of copy editing fixes it.
Step 2: Read the score
Low risk means send it. Medium risk means fix the listed issues first; usually it is two or three trigger words and a missing signature. High risk means the email would probably be filtered and almost certainly ignored if it was not: rewrite it rather than patching it.
Step 3: Rewrite around the flags
The fix for almost every flag is the same: write less like a marketer and more like a person. Replace "limited time offer" with a date. Replace "guaranteed results" with a number from a real client. Cut the second link. Add your name and your company at the bottom. Then run it again.
Step 4: Check the list as carefully as the copy
A clean email to a dirty list still bounces, and bounces hurt your domain more than trigger words do. Verify addresses with the Email Validator before the sequence starts, and if you found the contacts on LinkedIn, the LinkedIn Profile Scraper returns the profile details that let you write the personalised first line the checker is looking for.
A simple structure that passes
One line that proves you know who they are. One sentence on the problem you solve for people like them. One sentence of proof with a number. One easy question. Your name, your company, one link, an opt-out line. Five short paragraphs, under 120 words, no formatting. It scores clean and, more importantly, it gets replies.
When you want someone else to run it
Writing, testing and sending cold email at volume while keeping domains healthy is a full-time job. It is the one we do in our cold outbound campaigns: list building, copy, warm-up, sending infrastructure and reply handling, so your team only sees the conversations.
Check your next cold email before you send it. Thirty seconds, no signup.
