The /etc/oddjobd.conf.d/oddjobd-mkhomedir.conf is typically processed along with other files in the /etc/oddjobd.conf.d directory.
The mkhomedir helper itself accepts these options:
Refrain from outputting the usual "Creating home directory..." message when it creates a home directory.
Only create the home directory; do not populate it using the contents of the skeleton directory.
Override the location of the skeleton directory (by default: /etc/skel).
Specify a umask whose bits are masked off of contents of the skeleton directory while they are copied to the user's new home directory. The default is read from /etc/login.defs by taking HOME_MODE and UMASK values, in this order. First found value persists.