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OSSEC / HIDS Rule 3356

OSSEC / HIDS rule catalog

  • Rule family: OSSEC / HIDS
  • Rule ID: 3356
  • Definition status: Present in current source
  • Alert message / subject: Postfix: Multiple attempts to send e-mail from black-listed IP address (blocked).
  • Rule level: 10
  • Definition checked: 2026-10-21
  • Configured frequency: $POSTFIX_FREQ
  • Timeframe (seconds): 120
  • Ignore interval (seconds): 30

Correlation values are configuration attributes; event-count behavior depends on the manager version and parent rules.

Interpretation and response

This event is recorded as “Postfix: Multiple attempts to send e-mail from black-listed IP address (blocked).” Review the originating log and the affected host or service to determine whether the activity was expected.

An OSSEC/HIDS event records or correlates activity. Blocking depends on the originating application and any separately configured Active Response policy; an alert alone does not prove that an attack was blocked.

Documentation

The following guidance was migrated from the historical wiki and reviewed against the rule definition. Legacy ASL product names and interface instructions refer to the versions documented then. Use the current metadata above and your installed configuration when interpreting thresholds, notification settings and response behavior.

Rule ID

3356

Status

The wiki marked this rule Active at the source revision. Current definition status is shown above.

Alert Message

Postfix: Multiple attempts to send e-mail from black-listed IP address (blocked).

Description

This rule detects if your antispam email solution has blocked an IP address 10 or more times 120 seconds. When this occurs, if ASL is configured to take Active Response measures it will do so. By default this means the IP address will be blocked by the firewall by 600 seconds.

False Positives

None.

Tuning Guidance

Contact your email antispam vendor for assistance if this IP address is not sending spam.

Source and revision

Migrated from HIDS_3356, wiki page 650, revision 5630 (20160210). Documentation review: 2026-10-21. An archived wiki status of Active is not a current deployment status.

For assistance, provide the rule ID, installed product and rule version, and a sanitized event to Atomicorp support .