Transport rules
This section describes the configuration of remote connectors within Exchange Online associated with systems built according to guidance in ASD's Blueprint for Secure Cloud.
Estimated reading time: 2 minutes
Instruction
The below tables outline the as built configuration for ASD’s Blueprint for Secure Cloud for the Microsoft Exchange Online portal blade at the following URL:
https://admin.exchange.microsoft.com/#/transportrules
The settings described on these pages should be used to provide reference to a baseline implementation for a system configured using the Blueprint. Any implementation implied by these pages should not be considered as prescriptive as to how an organisation must scope, build, document, or assess a system.
Implementation of the guidance provided by the Blueprint will differ depending on an organisation’s operating context and organisational culture. Organisations should implement the Blueprint in alignment with their existing change management, business processes and frameworks.
Placeholders such as <ORGANISATION.GOV.AU>, <BLUEPRINT.GOV.AU> and <TENANT-NAME> should be replaced with the relevant details as required.
Rule conditions
| Item | Value |
|---|---|
| Name | Require TLS for sensitive items |
| Apply this rule if | |
| - The recipient | is external/internal |
| - The recipient is located | Outside the organisation |
| And | |
| - The message headers… | includes any of these words |
| - Header Name | msip_labels |
| - Words or phrases | All OFFICIAL Sensitive GUIDs All PROTECTED GUIDs |
| Do the following | |
| - Modify the message security | Require TLS encryption |
Rule settings
| Item | Value |
|---|---|
| Priority | 0 |
| Rule mode | Enforce |
| Severity | |
| Match sender address in message | Header |
Note
To obtain a list of all sensitivity label GUIDs for the above rule, organisations can use the Security & Compliance PowerShell. The following command will publish the label name and its associated GUID.
Get-label | Select displayname,guid
Related information
Security & Governance
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Design
Configuration
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