Help me in correcting sendmail.cf

UNIX AIX
1

Hi all,
In AIX I need to set the below two as of now these are not.
1)Opnoexpn is not set in sendmail.cf
2)Opnovrfy is not set in sendmail.cf

Please let me know the steps to set Opnoexpn and Opnovrfy in sendmail.cf

Thanks and Regards,
Pavankumar