The PRMMBX privilege lets the user's process
create or delete a permanent mailbox by executing the Create Mailbox
and Assign Channel ($CREMBX) system service or the Delete Mailbox
($DELMBX) system service. The privilege also allows the creation of
temporary mailboxes with the $CREMBX service.
Mailboxes are buffers in virtual memory that are
treated as if they were record-oriented I/O devices. A mailbox is
used for general interprocess communication.
Do not grant PRMMBX to all users of the system.
Permanent mailboxes are not automatically deleted when the creating
processes are deleted and, thus, continue to use a portion of system
dynamic memory. System performance degrades as system dynamic memory