The TMPMBX privilege lets the user's process create a temporary
mailbox by executing the Create Mailbox and Assign Channel ($CREMBX)
system 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. Unlike a permanent mailbox,
which must be explicitly deleted, a temporary mailbox is deleted
automatically when it is no longer referenced by any process.
Grant this privilege to all users of the system to facilitate
interprocess communication. System performance is not likely to
be degraded by permitting the creation of temporary mailboxes, because
their number is controlled by limits on the use of system dynamic
memory (BYTLM quota).
HP OpenVMS Guide to System Security
Security for the System Administrator
