New Zealand Information Security Manual (NZISM) 15.1.14.C.01: 15.1.14.C.01 Contact originator of unmarked government email

When an email without a marking comes from a government agency, whether in New Zealand or overseas, personnel should get in touch with the sender to establish how it ought to be handled.

Maintained by Gerard BlokdykVerified against the published standard 31 May 2026Control text last updated 21 May 2026

Other controls in Chapter 15: Email security – New Zealand Information Security Manual (NZISM)

15.1.10.C.01 15.1.10.C.01 Restrict selectable markings to the system's accreditation level
15.1.10.C.02 15.1.10.C.02 No automatic marking insertion without user action
15.1.10.C.03 15.1.10.C.03 Prevent downgrading markings on replies and forwards
15.1.11.C.01 15.1.11.C.01 Every email carries a protective marking
15.1.11.C.02 15.1.11.C.02 Email marking reflects the highest classified element
15.1.11.C.03 15.1.11.C.03 Place marking in subject line or header
15.1.12.C.01 15.1.12.C.01 Assess unmarked email received from outside government
15.1.13.C.01 15.1.13.C.01 Do not mark purely personal emails

Query this from an agent

The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.

MCP endpoint All New Zealand Information Security Manual (NZISM) controls