Transport SMTP Send Connector

In Microsoft Exchange Server 2013/2016, a Send connector controls the flow of outbound messages to the receiving server. Exchange 2013/2016 Mailbox servers running the Transport service require Send connectors to deliver messages to the next hop on the way to their destination. Slow and error-prone connectors can therefore obstruct the timely delivery of mails to the end point. This is why, it is imperative that administrators identify such problematic connectors quickly, clear the bottleneck rapidly, and ensure that email delivery is not impeded in any way. This is where the Transport SMTP Send Connector test helps. This test auto-discovers the send connectors of the Transport service, and for each connector, reports the message load on that connector, reveals how well the connector handles the load, captures errors/failures experienced by the connector, and thus points administrators to those connectors that are unable to handle the load or are error-prone. In the process, the test enables administrators to figure out where email delivery is bottlenecked.

Target of the test : A Microsoft Exchange 2013/2016 server

Agent deploying the test : An internal agent

Outputs of the test : One set of results for each Transport SMTP send connector

Configurable parameters for the test

Test period - How often should the test be executed Host - The host for which the test is to be configured. port – The port at which the host listens.

Measurements made by the test

Measurement	Description	Measurement Unit	Interpretation
Data sent rate:	Indicates the rate at which data was sent by this connector.	KB/sec	A high value over a period is indicative of an excessive use of the SMTP server. Under such circumstances, compare the value of this measure across send connectors to know which connector is contributing to the heavy load on the SMTP server.
Outbound connections from the send connector:	Indicates the number of outbound connections from this send connector.	Number	The value of this measure indicates the connection load imposed by the send connectors of the Transport service on the next hop en-route to the destination. In the event of a connection overload, you may want to compare the value of this measure across send connectors, to know which send connectors have established the maximum number of connections.
Messages sent by send connector:	Indicates the rate at which messages are sent by this send connector.	Msgs/Sec	Compare the value of this measure across send connectors to know which send connectors are processing messages very slowly. In the event of a slowdown, this measure will lead you to the exact connector that could be contributing to the slowdown.
Connection failures encountered by send connector:	Indicates the number of connection failures currently encountered by this send connector.	Number	Ideally, the value of this measure should be 0.
DNS errors encountered by send connector:	Indicates the number of DNS errors currently encountered by this send connector.	Number	Ideally, the value of this measure should be 0.
Protocol errors encountered by send connector:	Indicates the number of protocol errors currently encountered by this send connector.	Number	Ideally, the value of this measure should be 0.
Socket errors encountered by the send connector:	Indicates the number of socket errors currently experienced by this send connector.	Number	Ideally, the value of this measure should be 0.