Details

Email system availability depends in part on best practice strategies for setting tuning configurations. This configuration controls the number of idle minutes before the connection is dropped. It works in conjunction with the Maximum Outbound Connections Count setting.

Connections, once established, may incur delays in message transfer. The default of 10 minutes is a reasonable window in which to resume activities without maintaining idle connections for excessive intervals. If the timeout period is too long, idle connections may be maintained for unnecessarily long time periods, preventing new connections from being established. Sluggish connectivity increases the risk of lost data. A value of 10 or less is optimal.

Solution

Update the EDSP.

Open the Exchange Management Shell and enter the following command:

Set-SendConnector -Identity <'IdentityName'> -ConnectionInactivityTimeOut 00:10:00

Note: The value must be in quotes.

or

The value as identified by the EDSP that has obtained a signoff with risk acceptance.

Repeat the procedure for each Send connector.

Supportive Information

The following resource is also helpful.

• https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_MS_Exchange_2013_Y21M01_STIG.zip

This security hardening control applies to the following category of controls within NIST 800-53: System and Communications Protection.This control applies to the following type of system Windows.

References

• 800-53|SC-5(2)
• CAT|II
• CCI|CCI-001095
• Rule-ID|SV-84441r1_rule
• STIG-ID|EX13-EG-000095
• Vuln-ID|V-69819

Source

• Tenable.com/audits