Works with Mailgun

Spam Score Checker for Mailgun: Free Browser-Based Tool

Q: Is there a free way to spam-trigger analysis for Mailgun campaigns?

Yes. The MiN8T Spam Score Checker below runs entirely in your browser — no signup, no upload, and the output works with any Mailgun workflow.

→ Open the free Spam Score Checker

Browser-only, no signup, no upload. Output works with any Mailgun campaign.

Built by the MiN8T Engineering Team · Updated 28 May 2026

MiN8T Spam Score Checker interface preview

Mailgun's built-in tools cover the basics, but the spam score checker workflow often benefits from a dedicated, browser-only preprocessor before uploading. Pre-send spam-trigger analysis catches issues before they impact your sender reputation. Free rule-based scoring combined with a Naive Bayes classifier identifies precisely which content triggers fire.

Why pre-process before uploading to Mailgun

Mailgun does not offer pre-send rule scoring. External free tools fill this gap.

Step-by-step: spam-trigger analysis for Mailgun

Paste your campaign HTML into the free spam score checker below
60+ rules evaluate subject patterns, body keywords, header completeness, link density, HTML structure, image-to-text ratio, and authentication signals
A Naive Bayes classifier trained on 50,000+ labeled messages provides a complementary spam-probability score
Review the rule-by-rule breakdown and fix triggers before sending via Mailgun

Mailgun-specific deliverability quirks to know

Mailgun is API-first transactional + marketing. Pre-send hygiene scoring is essential since you control the HTML directly.

Frequently asked questions

Does Mailgun include a built-in spam score checker?

Mailgun provides basic functionality but lacks granular control. Mailgun does not offer pre-send rule scoring. External free tools fill this gap.

Is there a free way to spam-trigger analysis for Mailgun campaigns?

Yes. The free MiN8T Spam Score Checker runs entirely in your browser — no signup, no upload, no rate limits. The output is a standard file you can upload directly to Mailgun.

What image size limit does Mailgun enforce?

Mailgun accepts uploads up to 5000 KB per image and recommends a max width of 600px for email body width. Supported formats: JPG, PNG, GIF, WebP.

Does Mailgun verify SPF, DKIM, and DMARC automatically?

Mailgun requires SPF and DKIM via DNS. DMARC monitoring is available on their Foundation plan and higher.

What about subject line analysis for Mailgun?

Mailgun does not offer subject line analysis. External tools provide it. Use the free subject line analyzer for length scoring, spam-trigger detection, and sentiment analysis before pasting into Mailgun.

Related free tools

While preparing your Mailgun campaign, you may also want:

Image Compressor — also free, browser-based, optimized for email marketers
GIF Compressor — also free, browser-based, optimized for email marketers
CSS Inliner — also free, browser-based, optimized for email marketers
Inbox Preview — also free, browser-based, optimized for email marketers