Inbound Communication and Abuse Management Policy (UK)

Inbound Communication and Abuse Management Policy (UK)

Version: 1.1 Effective Date: December 12, 2025 Owner: Security and Compliance Team

I. Policy Objective and Scope

This policy establishes mandatory operational guidelines for identifying, classifying, and mitigating risks arising from unsolicited, fraudulent, or abusive electronic messages received by the organization's public-facing and internal email addresses. This policy's scope is strictly inbound email communications originating from members of the public.

Jurisdiction Focus: While respecting global standards, this policy emphasizes compliance with UK-specific regulations relevant to anti-fraud and cyber security, including the Computer Misuse Act 1990 (malicious communication) and obligations under data protection laws (e.g., GDPR) concerning the handling of received personal data.

The Security and Compliance Team (including Anti-Fraud Investigators) is exclusively responsible for the implementation, technical enforcement, and investigation of all breaches or violations related to inbound communication integrity.

II. Definitions

  • Inbound Commercial Message (ICM): Any unsolicited email, particularly those sent in bulk, promoting non-relevant commercial activities to company staff (a form of "inbound spam").

  • Malicious Communication: Any inbound message containing known malware, links to phishing sites, social engineering tactics, or attachments intended to compromise company systems or data (e.g., ransomware, credential harvesting).

  • Abusive Communication: Messages containing threats, harassment, defamatory content, or excessive volume intended to disrupt business operations.

  • False Communication (Fraud): Messages impersonating vendors, clients, or internal staff attempting to solicit sensitive information or financial transfers (e.g., Business Email Compromise/BEC attempts).

  • Whitelist/Blacklist: Managed lists of trusted/untrusted email senders and domains maintained by the Security Team to manage inbound mail flow.

III. Mandatory Inbound Security and Filtering Requirements

The Security Team must maintain the following technical controls to manage inbound risk:

  • Advanced Filtering: Implement and continuously update machine learning and signature-based email security gateways capable of detecting known malware, zero-day threats, and sophisticated phishing campaigns.

  • Sender Authentication: Enforce strict DMARC, DKIM, and SPF validation policies on all incoming emails. Messages failing authentication from known partners/vendors must be quarantined or rejected.

  • Quarantine Management: Maintain a secure quarantine system for suspicious emails, accessible only by the Security Team, to prevent employee exposure while allowing for investigative review.

  • User Reporting Mechanism: Provide a clear, one-click mechanism for employees to securely report suspicious emails directly to the Security Team for triage and analysis.

  • Whitelisting Exception: All requests for whitelisting a domain or address must be reviewed and approved by the Security Team based on business necessity and verification of sender legitimacy.

IV. Classification and Handling of Inbound Violations

All inbound communication flagged as suspicious must be immediately classified by the Security Team's triage process:

Classification

Description of Violation

Security Team Action

Inbound Spam (ICM)

High volume, unsolicited marketing, irrelevant bulk messages.

Automatically filtered/quarantined. If volume is excessive, permanently blacklist the sending IP/domain.

Malicious/Phishing

Contains malware, credential harvesting links, or suspicious attachments.

Immediate mandatory action: Global block of sender IP/domain; quarantine or auto-delete messages; notify impacted users.

False Communication

BEC or invoice fraud attempts; impersonation of executives, legal, or finance.

Urgent investigation required: Alert Anti-Fraud Investigators. Preserve full message headers and content as evidence.

Abusive/Harassment

Targeted threats, harassment, or defamatory content directed at an employee or the company.

Preserve evidence; notify Legal and HR departments; permanent sender block; potential reporting to law enforcement (UK Police/Action Fraud).

V. Investigator Protocol for Inbound Abuse (Security Team Action)

In the event of a Malicious, False, or Abusive Communication (Level 1 or Level 2 risk), the Security Team's Anti-Fraud Investigators must execute the following evidence preservation and tracing protocol:

  1. Isolation and Preservation:

    • Do not reply to the suspicious email.

    • Preserve the email in its native format, including all headers, timestamps, and message routing paths.

    • Isolate any attached files in a secure sandbox environment for analysis; never open on a corporate device.

  2. Origin Tracing:

    • Analyze the full message headers to identify the originating IP address and associated geographical region (country/ISP).

    • Determine if the sending domain uses spoofing (DMARC failure) or is a lookalike domain (typosquatting).

  3. Cross-Referencing:

    • Cross-reference the sender's details against internal incident logs, global threat intelligence feeds, and fraud databases.

    • If financial loss is a risk, liaise immediately with the Finance department to halt any pending payments related to the suspect communication.

  4. Reporting and Remediation:

    • Immediately apply a global block (IP and Domain) to prevent future contact.

    • Generate a detailed incident report containing all preserved evidence, classification, and tracing results.

    • Liaise with external authorities (e.g., the National Cyber Security Centre, Information Commissioner's Office, or Action Fraud in the UK) if the communication violates the Computer Misuse Act or represents a sustained, credible threat.