PMDF QM is a utility program which allows inspection and manipulation of queued messages. While QM has two modes, maintenance mode and user mode, unprivileged users can only use the user mode. From user mode, you can obtain listings of all "queued" messages which you have sent but which are still on your system awaiting delivery.2 You can read or return any of your queued messages, and, in the case of outgoing PMDF-FAX messages, change FAX telephone numbers.
Note that this utility merely reports on messages in PMDF's delivery queues. That a message you have sent no longer appears in PMDF's queues, does not imply that it has reached its final destination. All that it means is that the message has left the PMDF system and is no longer under PMDF's control. For example, it is not uncommon for a message to make an intermediate stop on another system such as a mail hub. In such cases, PMDF will consider the message to be "delivered" when it hands the message and responsibility for it off to the intermediate system.
To run PMDF QM, issue the command
$ PMDF QM
9.2.1 Available User Mode Commands
In this section, the available user mode PMDF QM commands are
|DATE||Show current date and time|
|DIRECTORY||List currently queued messages|
|EDIT_FAX||Edit a queued PMDF-FAX message|
|EXIT||Exit the utility|
|HISTORY||Display message delivery history information|
|QUIT||Exit the utility|
|READ||Display message envelope and header information|
|RETURN||Return a message to its originator|
|SPAWN||Spawn a subprocess|
2 Usually, when you send a message an immediate attempt is made to deliver it. Should that attempt fail owing to a temporary problem such as a network outage, the message will be queued in the mail system's delivery queues. Subsequent, periodic attempts will be made to deliver the message until either it is delivered or it is determined to be undeliverable in which case it is returned to you. Messages are typically returned as undeliverable because the address turns out to be incorrect; e.g., the destination system does not recognize the recipient address or the destination system is unreachable.