How can I check the potential spam score of my email?

You've built the campaign, written the subject line, and you're about to hit send. But how do you know if a spam filter is going to intercept it before it ever reaches the inbox? That's exactly what spam score checkers are for.

A spam score is a number that reflects how many spam-like signals your email triggers. The most widely used scoring engine is SpamAssassin, which awards points for things like spammy phrases, broken authentication, suspicious links, and poor formatting. The higher the score, the more likely filters are to block or divert your email.

Here are the tools worth knowing about.

Mail-Tester is the quickest free option. It gives you a unique test address. You send your actual email to that address, then check the results page. You'll see a score out of 10 (higher is better here, which is the opposite of SpamAssassin's raw point system), plus a breakdown of exactly what triggered issues. Authentication failures, missing unsubscribe links, blacklisted IPs, suspicious content. It surfaces all of it. For most senders, a 9 or 10 out of 10 means you're in good shape.

GlockApps goes further. It tests inbox placement across major providers including Gmail, Outlook, and Yahoo Mail, and shows you which folder your email landed in. Inbox, spam, or promotions tab. It also includes spam score reporting. GlockApps is paid, but worth it if you're sending at any real volume and want to know what's actually happening at the mailbox level.

Postmark has a free spam check API that runs your content against SpamAssassin rules and returns the raw score with a rule-by-rule breakdown. It's more technical than Mail-Tester but very useful if you want to understand exactly which rules your email is triggering.

Mailtrap is a developer-focused testing environment that includes spam analysis as part of its email sandbox. If your team is already using it for QA, the spam check is built right in.

Many ESPs also include built-in pre-send checks. Mailchimp, Klaviyo, and Brevo all flag potential issues before you send. Though the depth of feedback varies by platform.

Now when you look at your results, don't just chase the number. Read the breakdown. A missed SPF record or a failing DKIM signature will hurt your score (and your deliverability) far more than a single flagged phrase. Fix the authentication issues first, then clean up the content signals.

Want to know what score actually crosses the line into "probably spam"? That's covered in the question on scoring thresholds. Or if you want a second set of eyes on a campaign that keeps failing, our SOS hotline is free and we actually pick up.