The non-set-user-id root version of sendmail used for local mail submission employs a queue that is located separately from that used by the MTA daemon. This separate queue is located by default in /var/spool/clientmqueue. If you prefer a different location or name you can redefine it with this confMSP_QUEUE_DIR Build macro. Two ways to redefine it might look like this:

define(`confMSP_QUEUE_DIR',`/var/spool/mspqueue')            change the name
define(`confMSP_QUEUE_DIR',`/disk1/spool/clientmqueue')      change the location

Note that by renaming or relocating the queue directory with this confMSP_QUEUE_DIR Build macro the MSP_QUEUE_DIR mc macro must also be updated when building the submit.cf file.