Cold Email Deliverability Checker: Spam Words and Warmup

Auditing cold email deliverability: DNS, spam words and warmup

The tool gives a score out of 100: a 30-point base, plus 15 points each for SPF, DKIM, DMARC and continuous warmup and 10 for a custom tracking domain, minus 8 points for each risky phrase found in your message. It also plans a 4-week ramp-up: 5, 12, then 22 sends per inbox per day before the target pace.

How the score is calculated

Score = 30 + 15 (SPF) + 15 (DKIM) + 15 (DMARC) + 10 (custom tracking domain) + 15 (continuous warmup), then −8 per risky phrase, −10 if a word has at least four capital letters in a row and −8 beyond two exclamation marks. The result is kept between 10 and 100: 80 and above, primary inbox likely; 60 to 79, risk of the Promotions tab; below 60, spam risk.

Worked example

Three inboxes at 35 sends a day, with SPF, DKIM, DMARC and warmup ticked but no tracking domain: 90 points before the text is analysed. A message containing “free” and “urgent” with three exclamation marks loses 2 × 8 + 8 = 24 points and drops to 66, in the Promotions zone. The schedule gives 15, 36 and then 66 sends a day for the fleet during the first three weeks, then 105 a day, or 2,310 emails over 22 working days.

Assumptions and limits

The DNS boxes are declarative: the tool does not query your records. The list holds 21 French and English phrases matched as whole words (“freelance” does not trigger “free”), although “100% gratuit” counts twice, along with “gratuit”. Spanish or German words are not recognised, and accented capitals escape the all-caps rule. The weights are the tool's own; the 35 to 40 sends per inbox ceiling is an industry benchmark, not a mailbox provider rule. To put a figure on the sales impact of better deliverability, use the cold email prospecting simulator.

Sources and dates: Google's sender guidelines for Gmail and the Yahoo Sender Hub best practices, enforced since February 2024. Every sender must set up SPF or DKIM and keep complaints below 0.3%; DMARC (p=none accepted), SPF and DKIM together and one-click unsubscribe are required for bulk senders, meaning more than 5,000 messages a day to Gmail (checked on 14/10/2026).

Frequently Asked Questions

How many cold emails should I send per inbox per day?

The tool accepts 10 to 50 sends per inbox and starts at 35. It plans 5 sends a day in week one, 12 in week two, 22 in week three and the target pace from week four. The 35 to 40 per inbox ceiling is industry practice; Gmail and Yahoo mainly set a complaint rate below 0.3%.

Are SPF, DKIM and DMARC mandatory for sending to Gmail?

Since February 2024, every sender must set up SPF or DKIM. Above 5,000 messages a day to Gmail, you need SPF and DKIM, a DMARC policy (p=none is enough), an aligned From domain and one-click unsubscribe for marketing messages. Yahoo applies similar rules to bulk senders.

How is the deliverability score calculated?

It starts at 30 points and adds 15 for each of SPF, DKIM, DMARC and continuous warmup, plus 10 for a custom tracking domain. It removes 8 points per risky phrase, 10 for an all-caps word and 8 beyond two exclamation marks. At 80 or more the tool expects the primary inbox; below 60, spam.

Why is a word in my message flagged?

The tool looks for 21 French and English phrases as whole words: “free” is flagged, but “freelance” is not. Each phrase found costs 8 points. Likewise, the French “100% gratuit” is counted twice along with “gratuit”. Check the list of flagged words before editing your message.

Is this tool really free?

Yes, all tools on Kristools are 100% free and accessible without registration.

Is my data protected?

Yes. All processing is performed directly and securely inside your browser. No personal data is sent to our servers.