This topic details the metrics for the SMTP service.
Availability - The agent reports an SMTP service available if it can connect to it and read the welcome banner.
All Inbound Connections - Number of inbound connections of all types to the service.
All Outbound Connections - Number of outbound connections of all types from the service.
Inbound Connections - Number of inbound TCP connections to the service.
Outbound Connections - Number of outbound TCP connections from the service.
Response Time - The time (in ms) it took to determine service availability.
TCP connection state metrics - The number of connections in each connection state is reported: