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MailFleet

Free tools

SpamAssassin checker — pre-send spam score & rule analysis

Paste your subject and HTML or plain-text body to get a SpamAssassin-style spam score, triggered rules, and fix recommendations before you send from MailFleet or any other sender.

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At a glance

What it is
Pre-send SpamAssassin-style content analyzer with spam score, triggered rules, and recommendations.
Who it is for
Email marketers, agencies, and ops teams preparing campaigns in MailFleet or any desktop sender.
Main capabilities
Subject/body analysis, HTML editor, optional headers, spam score gauge, rules table, captcha, rate limits.
Platforms
Browser-based SpamAssassin analysis on mailfleet.app when the live check service is available.
Responsible use
For permission-based email content only. A low score is not a guarantee of inbox placement.

Pre-send SpamAssassin analysis

Score your subject and body before sending. Captcha required. Credentials are not stored.

Message content

Hi there,

Here is your permission-based update with one helpful link.

Unsubscribe

Security verification

Type characters from the image. Case-insensitive.

Verification challenge
Run analysis to see spam score, triggered rules, and recommendations here.

Free SpamAssassin analysis on mailfleet.app when the live check service is available. Use only content and accounts you are authorized to test. Learn more: Apache SpamAssassin.

Capabilities

Catch spam signals before you send

Score, rules, and recommendations in one workflow — aligned with how MailFleet runs pre-send checks in the desktop app.

  • Spam score & threshold

    See total score vs the default 5.0 threshold — the same baseline most SpamAssassin deployments use.

  • Triggered rules table

    Review rule names, point values, and descriptions for subject, body, links, HTML, and header issues.

  • HTML & plain text

    Compose with the rich text editor or paste plain text. Optional From address and raw headers for deeper checks.

  • Fix recommendations

    Get specific next steps — caps in subject, link density, unsubscribe headers, and spam phrase rewrites.

  • spamc when available

    If spamc is installed on the server, the tool uses your local SpamAssassin install for the score.

  • Abuse-resistant

    Image captcha, session verification, and per-IP rate limits keep the public checker safe.

How to use

Five steps to a cleaner spam score

  1. 1

    Enter subject & body

    Paste the subject line and HTML or plain-text content from your template.

  2. 2

    Add optional context

    Set From address or paste raw headers for List-Unsubscribe and Message-ID checks.

  3. 3

    Solve captcha

    Complete the image challenge before running the analysis.

  4. 4

    Run analysis

    Review score, triggered rules, and recommendations.

  5. 5

    Fix & re-test

    Adjust content and re-run until score is comfortably below threshold.

What is a SpamAssassin score?

SpamAssassin applies hundreds of rules to email content and headers, assigning positive or negative points. The total spam score is compared to a threshold (commonly 5.0). At or above threshold, mail is more likely to be filtered.

Pre-send checks help you catch obvious content problems before they affect reputation — especially subject lines, link density, HTML-only layouts, and missing unsubscribe signals.

When to run a pre-send check

Run checks after template changes, before a new campaign launch, when moving to a new provider, or when bounce/filter rates increase without DNS changes.

  • New newsletter or promotional template
  • After agency handoff or brand refresh
  • Before high-volume permission-based sends
  • When SpamAssassin flags appear in provider logs

What this tool does not guarantee

A low score does not guarantee inbox placement. Authentication (SPF, DKIM, DMARC), list permission, engagement, and sender reputation still matter.

The built-in rules engine covers common signals. Install spamc on your server for scores aligned with your production SpamAssassin configuration.

Key takeaways

  • Default SpamAssassin threshold is 5.0 — aim lower for marketing mail.
  • Triggered rules show exactly what raised your score.
  • Use HTML or plain text; optional headers for unsubscribe checks.
  • Low score does not guarantee inbox placement — validate DNS auth too.

For regulatory context on commercial email in the United States, see the FTC CAN-SPAM compliance guide.

Delivery note: MailFleet helps users manage campaigns through their own sending providers. Delivery outcomes depend on sender reputation, DNS authentication, content quality, recipient engagement, list quality, provider rules, and mailbox filtering systems.

Frequently asked questions

Many filters use 5.0 as default threshold. Aim below 3.0 for marketing mail; lower is better. Re-test after each template change.

Get started

Run SpamAssassin checks in MailFleet

Integrated pre-send checks, campaign logs, and provider profiles — all from your desktop.

Download MailFleetSpamAssassin product page

Available on

  • Windows 10+
  • macOS 12+
  • Linux (DEB & RPM)

Same desktop experience across every platform — one workflow for your entire team.