Title

Message size restriction is specified at the SMTP connector level. . (Cat II impact)

Discussion

E-mail system availability depends in part on best practices strategies for setting tuning configurations. For message size restrictions, multiple places exist to set or override inbound or outbound message size. Failure to control the configuration strategy can result in loss of data or system availability. This setting enables the Administrator to control the maximum size of outgoing messages on an SMTP Connector. It is recommended that, in general, no limits are applied at the connector level. This is done so that connectors do not end up prohibiting the delivery of messages that would otherwise be permitted by the Exchange configuration at the virtual server level. Using connectors to control size limits at an enterprise-wide level is discouraged since the limits would need to be applied to every potential connector in order to create an effective enterprise-wide limit.

Check Content

Review SMTP connectors. Procedure: Exchange System Manager >> Administrative Groups >> [administrative group] >> Routing Groups >> [routing group] >> Connectors >> [SMTP Connectors] >> Properties >> Content Restriction tab >> Allowed Sizes The 'Only messages less than (KB)' checkbox should be cleared. Criteria: If the 'Only messages less than (KB)' checkbox is cleared, this is not a finding.

Fix Text

Configure the SMTP connectors. Procedure: Exchange System Manager >> Administrative Groups >> [administrative group] >> Routing Groups >> [routing group] >> Connectors >> [SMTP Connectors] >> Properties >> Content Restriction Tab >> Allowed Sizes Clear the 'Only messages less than (KB)' checkbox.

Additional Identifiers

Rule ID: SV-21038r1_rule

Vulnerability ID: V-19198

Group Title:

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.