# SI-08 Spam Protection — NIST 800-53 Rev5 control

> FedRAMP Consolidated Rules for 2026 v2026.07.14.01 · updated 2026-07-14
> Canonical page: /control/si-8

Canonical id: `si-8` · family `SI`

> a. Employ spam protection mechanisms at system entry and exit points to detect and act on unsolicited messages; and b. Update spam protection mechanisms when new releases are available in accordance with organizational configuration management policy and procedures.

_Control title and statement: NIST SP 800-53 Rev5 catalog (the pinned commit is in `/api` under `control_text`). The FedRAMP rules reference these controls by id only; everything below is what FedRAMP says about this id._

## Rev5 baseline membership

- certification class C
- certification class D

## Key Security Indicators that reach it

- `KSI-CNA-RNT` — Restricting Network Traffic (Cloud Native Architecture)
  Machine-based information resources are persistently reviewed to ensure they are appropriately configured to limit inbound and outbound network traffic.
- `KSI-CNA-RVP` — Reviewing Protections (Cloud Native Architecture)
  The effectiveness of protection against denial of service attacks and other unwanted activity for machine-based information resources is persistently reviewed.

## FedRAMP guidance

{
  "guidance": [
    "When CSO sends email on behalf of the government as part of the business offering, Control Description should include implementation of Domain-based Message Authentication, Reporting & Conformance (DMARC) on the sending domain for outgoing messages as described in DHS Binding Operational Directive (BOD) 18-01. https://www.cisa.gov/news-events/directives",
    "SI-8 Guidance: CSPs should confirm DMARC configuration (where appropriate) to ensure that policy=reject and the rua parameter includes reports@dmarc.cyber.dhs.gov.  DMARC compliance should be documented in the SI-08 control implementation solution description, and list the FROM: domain(s) when emails are sent on behalf of the government."
  ]
}