Spam Protection
Configure spam protection: thresholds, Bayes filter, RBL lists, and custom filter rules.
Spam Protection – Granular Configuration Options
The Conbool Guardian is a multi-layered system for protecting your mailboxes from unwanted emails.
It analyzes incoming messages based on various criteria, scores them with a spam score, and — depending on your configuration — executes the appropriate actions.
Activate Guardian
The main toggle for spam protection.
- Active
- Function: Enables or disables the Guardian globally.
- Setting:
- Toggle to the right (blue) → Guardian active
- Toggle to the left (gray) → Guardian disabled
Spam Score Thresholds & Behavior
Define at which score messages are flagged or blocked:
| Setting | Description | Example Value |
|---|---|---|
| Score at which emails are flagged | Starting from this value, an email is considered potential spam. It will be delivered but marked as spam. | 13 |
| Score at which emails are blocked | Starting from this value, an email is considered definite spam. The message will be blocked or moved to quarantine (depending on server configuration). If left empty, no blocking occurs. | 25 |
Options on Flagging
- Set Header (X-Conbool-Flag)
Adds additional headers such asX-Conbool-Spam: YesorX-Spam-Flag: YESto flagged messages.
Email clients can use these for their own filter rules. - Subject Prefix
Adds a notice to the subject of flagged emails.- Example:
[SPAM] Grab your offer now
- Example:
- Alternative Delivery Address (optional)
Forwards spam messages to a different address.- Useful for centralized analysis or archiving
- Example:
spam@conbool.com
Analysis & Filter Methods
Activate additional checks to increase detection accuracy.
Each method influences the spam score.
- Heuristic Filtering
Rule-based detection of typical spam patterns (e.g., suspicious phrasing). - Bayesian Filter
A learning, statistical filter.- Analyzes word frequencies in spam and ham emails
- Becomes more accurate through training with your own emails
- SURBL / URIBL
Checks URLs in emails against real-time blacklists of spam domains. - RBLs (Real-time Blackhole Lists)
Checks the sender's IP address against known spam sender databases.
Custom Filter Rules
- Custom Spam Words
Each match with these terms increases the spam score.- Example values:
- gambling
- winner
- Example values:
- Custom RegEx Expressions
For complex pattern matching with regular expressions.Example:
^.*(free Money|bitcoin).*
Detects emails containing the phrases free Money or bitcoin.
See Also
- Policies – Apply spam protection settings specifically to users or groups through policies.
- Quarantine – Configure quarantine for blocked messages.