Analyze your email for spam triggers, formatting issues, and deliverability risks before you hit send.
Score a message on the signals filters actually weigh, and see which parts of it are working against you. Free, no account.
NitroShock helps you audit your entire domain reputation, not just individual emails.
Get Started FreePaste a message and the checker evaluates it the way a filter would: the ratio of text to links, image-only bodies, the presence of an unsubscribe path, subject line patterns, attachment types, and the reputation of any domains you link to.
It also confirms whether the sending domain is authenticated, because content scoring is meaningless on a domain that cannot prove who it is. That part is covered in more depth by the record checker, which is also free.
SPAM SCORE 4.1 borderline
CONTENT
text to link ratio poor, 6 links / 84 words
image-only body no
all caps in subject no
urgency phrasing "act now", "limited time"
unsubscribe link missing
TECHNICAL
authenticated domain yes
link domains flagged 1 of 4 (shortener)
plain text alternative missing
PHYSICAL ADDRESS IN FOOTER missing
The two absences at the bottom cost more than the score suggests. A missing unsubscribe path and a missing postal address are not just filter signals, they are legal requirements in most places a commercial message will land, including under Canadian and US rules for commercial email. Fixing them is required regardless of what any score says.
Six links in eighty-four words is the content finding. That ratio reads as promotional to a filter no matter how legitimate the links are, and the fix is usually to cut five of them rather than to rewrite the copy.
Filters weigh sender reputation heavily, and reputation is built from how recipients behaved toward your previous messages: opens, replies, deletions without opening, and complaints. None of that is visible in the message you are testing, which is why a message can score well and still land in spam.
The things that actually move reputation are unglamorous. Send to people who asked. Remove addresses that bounce. Warm a new domain gradually rather than sending a thousand messages on day one. Reply rate matters more than volume, which is the honest argument for smaller and better-targeted outreach.
No tool can promise inbox placement, and any that does is describing something outside its control.
What score is safe?
Lower is better and there is no threshold that guarantees delivery, because content is only part of the decision.
My message scores well but still goes to spam.
Almost always sender reputation or list quality. Neither is visible in the message itself.
Do I need a plain text version?
It helps, and it costs nothing. HTML-only messages are marginally more suspicious to filters.
Is this tool free?
Yes, with no account and no limit.
This free tool is one slice of the job. The full kit - rank tracking, audits, competitor gaps, content, and your visibility across ChatGPT and Google's AI Overviews - runs on credits you only spend when you use them. Sign up and we'll drop 25 credits in your account to try the paid tools on us.