Sun Java System Messaging Server 6.3 Administration Guide

27.3.1 Monitoring End-to-end Message Delivery Times

Email needs to be delivered on time. This may be a service agreement requirement, but also it is good policy to have mail delivered as quickly as possible. Slow end-to-end times could indicate a number of things. It may be that the server is not working properly, or that certain times of the day experience overwhelming message loads, or that the existing hardware resources are being pushed beyond their capacity. Symptoms of Poor End-to-end Message Delivery Times

Mail takes a longer period of time to be delivered than normal. To Monitor End-to-end Message Delivery Times