Global inbound message size must be controlled.
An XCCDF Rule
Description
<VulnDiscussion>Email system availability depends in part on best practices strategies for setting tuning configurations. Message size limits should be set to 10 megabytes at most, but often are smaller, depending on the organization. The key point in message size is that it should be set globally, and it should not be set to ‘unlimited’. Selecting ‘unlimited’ on either field is likely to result in abuse and can contribute to excessive server disk space consumption. Message size limits may also be applied on SMTP connectors, Public Folders, and on the user account under AD. Changes at these lower levels are discouraged, as the single global setting is usually sufficient. This practice prevents conflicts that could impact availability and it simplifies server administration. </VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls>ECSC-1</IAControls>
- ID
- SV-44044r1_rule
- Severity
- Low
- Updated
Remediation - Manual Procedure
Open the Exchange Management Shell and enter the following command:
Set-TransportConfig -MaxReceiveSize 10MB
If an alternate value is desired, obtain signoff with risk acceptance and document in the EDSP.