Microsoft Exchange 2000 Operations Guide — Version 1.058
rarely greater than zero. A reading of greater than zero shows that the server is receiv-
ing more messages than it can process. If this number increases steadily over time, there
is probably a problem with the Exchange Store you are trying to deliver to.
◆Categorizer Queue Length – This shows the number of messages waiting for advanced
address resolution. After this, the messages either go to the local queue or are sent to
the routing engine to be delivered elsewhere. A high figure here compared to your
baseline can indicate message flow problems.
◆Inbound Connections Current – Shows the number of current inbound connections. If
this reading remains zero over time, then there may be network problems.
◆Message Bytes Sent/Second – Examine this figure in conjunction with other counters
and your baseline to determine if your SMTP Server is passing messages as quickly as it
should. If, for example, this figure is low, but queues leading to this transport are high,
then there is a problem with the SMTP transport.
◆Message Bytes Received/Second – Again, use this in conjunction with other counters
and your baseline to determine overall health. For example, there may be a problem
with the SMTP transport if a queue going into this transport is high while the Message
Bytes Received/Second is low.
◆Avg. retries/Msg delivered – When Exchange fails to deliver messages, those messages
enter a retry queue. The SMTP server is configured with a retry interval showing how
long the server will wait before a first retry, second retry, and so for th. This counter
shows how many messages are going into retry as a fraction of the overall messages
delivered. You should expect the figure to be close to zero. If large number of messages
are being retried, the figure will approach 1. This counter is therefore a good indicator
of general message delivery problems on your network.
◆Avg. retries/message sent – This counter is the same as the previous counter, except it
applies to outgoing messages as opposed to incoming ones.
MSExchangeMTA and MSExchangeMTAConnections
In a pure Exchange 2000 Server environment running in native mode, the
MSExchangeMTA and MSExchangeMTAConnections objects are not particularly impor-
tant. However, in cases of coexistence with Exchange Server 5.5, or where messages are
being relayed to and from X.400 recipients, you may want to measure the Messages/Sec
and Work Queue Length of the MSExchangeMTA object and the Queue Length of the
MSExchangeMTAConnections object.
In Exchange 2000 Server, you may find the Message Transfer Agent (MTA) shutting down
fairly frequently, especially if it cannot find a domain controller temporarily. To resolve
this problem, you may want to use the recovery actions option in services to restart the
service in the event of it being stopped.