To delete / clear queue of PowerMTA:


Use pmta delete
 
Syntax :

pmta delete [--dsn] [--queue=domain[/vmta] [--orig=addr] [--rcpt=addr]
[--jobId=id] [--envId=id] [--accounting]

Description :
                 Deletes recipients from the queue. Although "--queue"'s default is */*, the command
requires either --queue or --jobId to be entered explicitly, so that an accidental "pmta
delete" command doesn't delete the entire queue. Messages are marked in the accounting
file as deleted by administrator.
Options :
--dsn
specifies that a DSN report should be sent. Using this option may slow the
deletion process. No entry is written to the accounting file unless the --accounting
flag is used as well.
--accounting
specifies that deletion information should be written to the accounting file. Using
this option may slow the deletion process.
--queue
specifies which queue(s) to delete from, and defaults to all queues.
--orig
specifies that only recipients with the MAIL FROM address be deleted
--rcpt
specifies that only recipients with the RCPT TO address are to be deleted.
--jobId
specifies that only recipients with the given Job ID are to be deleted
--envId
specifies that only recipients with the given Envelope ID are to be deleted.
Example :
delete /queue=*/{default}
It is recommended to pause the queue, before you actually delete the queue:
 
pmta pause
 
Syntax :

pause queue */{default}

Description :
Pause delivery of messages in the queue, and holds them from being delivered. May be
run prior to injecting mail into PowerMTA so that mail may be held for later delivery or before delete the queue.
Example :
pause queue */{default}