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 becomes
scarce.
HP OpenVMS Guide to System Security
Security for the System Administrator
