EX13-EG-000100 - Exchange Outbound Connection Limit per Domain Count must be controlled.


Email system availability depends in part on best practice strategies for setting tuning configurations. This configuration controls the maximum number of simultaneous outbound connections from a domain and works in conjunction with the Maximum Outbound Connections Count setting as a delivery tuning mechanism. If the limit is too low, connections may be dropped. If the limit is too high, some domains may use a disproportionate resource share, denying access to other domains. Appropriate tuning reduces the risk of data delay or loss.

By default, a limit of 20 simultaneous outbound connections from a domain should be sufficient. The value may be adjusted if justified by local site conditions.


Update the EDSP.

Open the Exchange Management Shell and enter the following command:

Set-TransportService -Identity <'IdentityName'> -MaxPerDomainOutboundConnections 20

Note: The <IdentityName> value must be in quotes.


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

See Also


Item Details


References: 800-53|SC-5(2), CAT|II, CCI|CCI-001095, Rule-ID|SV-84443r1_rule, STIG-ID|EX13-EG-000100, Vuln-ID|V-69821

Plugin: Windows

Control ID: 311549107f7b31ba710678a6e17e0387edb6d79b5006466e3bb14d5f7712bf96