Mail-Tester

Single-message spam scoring for senders checking a template and its authentication before a campaign goes out.

Mail-Tester assigns a score to any email sent to a generated test address, breaking down SpamAssassin results, authentication records, content triggers, and blacklist status. It also publishes free standalone checkers for SPF, DKIM, DMARC, and BIMI. Paid accounts add a JSON API and an embeddable iframe for putting results inside another product.