Restrict Sensitive Emails in Distribution Lists
Confirm all members' nationalities before sending sensitive Australian data to email lists.
Plain language
When sending emails that include sensitive Australian Government information, it's crucial to ensure that everyone on the email list is allowed to see it. This helps prevent confidential data from accidentally reaching those who shouldn't have access, which could lead to security breaches or information leaks.
Framework
ASD Information Security Manual (ISM)
Control effect
Preventative
Classifications
NC, OS, P, S, TS
ISM last updated
May 2021
Control Stack last updated
19 Mar 2026
E8 maturity levels
ML3
Guideline
Guidelines for system monitoringSection
Event logging and monitoringTopic
Cable RegisterOfficial control statement
A cable register contains the following for each cable: - cable identifier - cable colour - sensitivity/classification - source - destination - location - seal numbers (if applicable).
Why it matters
Failing to maintain a detailed cable register can lead to misrouting sensitive data, compromising national security and breaching legal obligations.
Operational notes
Validate each cable entry includes identifier, colour, sensitivity/classification, endpoints, location and seal numbers; reconcile against physical/installed cables after changes.
Implementation tips
- The manager should create a list of email distribution groups frequently used for sensitive information. Then, ensure that HR provides details of each member’s nationality in these groups so that only appropriate recipients receive sensitive information.
- The IT team should set up a system to verify and document the nationality of email list members. This can include checking IDs or using HR records to ensure recipients meet the criteria for receiving sensitive emails.
- HR teams should regularly update the recipient list details, making sure the nationalities are kept current and accurate. This can be done by verifying records with employees during scheduled HR check-ins.
- Managers should conduct training sessions for employees responsible for sending emails, emphasising the importance of confirming list member nationalities before sending sensitive information.
- System administrators should configure email systems to flag or block sensitive emails from being sent to distribution lists that have not been verified. This could be set up by adjusting email system settings or implementing additional software checks.
Audit / evidence tips
-
Askthe documented process of how nationalities are verified before sending sensitive emails
Gooda detailed process document with step-by-step instructions and designated roles
-
Goodis a description of tools and processes, confirming they check nationalities and adjust distribution lists accordingly
-
Askto see a checklist or report from a recent internal training session on email distribution practices
-
Goodsystem will flag and prevent emails to unverified distribution lists
Cross-framework mappings
How ISM-0109 relates to controls across ISO/IEC 27001, Essential Eight, and ASD ISM.
ISO 27001
| Control | Notes | Details |
|---|---|---|
| layers Partially meets (1) expand_less | ||
| Annex A 5.14 | ISM-0109 requires confirming all members’ nationalities before sending sensitive Australian data to email distribution lists, to prevent ... | |
These mappings show relationships between controls across frameworks. They do not imply full equivalence or certification.