Lexmark X6150 Fax problems

I have a Lexmark X6150 All in one and I’m having trouble setting up the fax. I’m trying to make it so when a fax is incoming the fax machine picks it up, if it s phone call it send it to the phone. I tried all the setting on the machine and in the software bu the fax machine always seems to answer no matter what tpye of call it is. Has anyone experinced this problem? You input is greatly apprecaited. Thanks