PMDF has facilities to collect and monitor channel counters based upon the Mail Monitoring MIB, RFC 1566. These counters tabulate on a per channel basis the twelve items described in Table 31-3.

Table 31-3 Channel Counters

Field name	Description
RECEIVED_MESSAGES	The number of messages enqueued to the channel
SUBMITTED_MESSAGES	The number of messages enqueued by the channel
STORED_MESSAGES	The total number of messages currently stored for the channel
DELIVERED_MESSAGES	The number of messages dequeued by the channel
RECEIVED_VOLUME	The volume of messages enqueued to the channel as measured in PMDF blocks
SUBMITTED_VOLUME	The volume of messages enqueued by the channel as measured in PMDF blocks
STORED_VOLUME	The volume of messages currently stored for the channel as measured in PMDF blocks
DELIVERED_VOLUME	The volume of messages dequeued by the channel as measured in PMDF blocks
RECEIVED_RECIPIENTS	The total number of recipients specified in all messages enqueued to the channel
SUBMITTED_RECIPIENTS	The total number of recipients specified in all messages enqueued by the channel
STORED_RECIPIENTS	The total number of recipients specified in all messages currently stored for the channel
DELIVERED_RECIPIENTS	The total number of recipients specified in all messages dequeued by the channel

It is important to note that these counters generally need to be looked at over time noting the minimum values seen. The minimums may actually be negative for some channels. Such a negative value merely means that there were messages queued for a channel at the time that its counters were zeroed (e.g., the cluster-wide database of counters created). When those messages were dequeued, the associated counters for the channel were decremented therefore leading to a negative minimum. For such a counter, the correct "absolute" value is the current value less the minimum value that counter has ever held since being initialized.