This is from a club player's perspective -
If the serve hits low down on the side wall behind the back of the service box the rally usually finishes there; and this is what the server will be trying to do. Jethro's recommended receiving position is not near enough to the side wall to volley a hard low serve hitting the side wall low opposite him.
I recommend that the left foot should be in line with the right line of the service box: this means that 1 step will allow you to volley anything hitting the side wall opposite you or further back.
You do have to be ready to move towards the centre of the court if necessary to deal with a body serve or one hitting the side wall early.
I do agree with his comments that the receiving position should be open and it’s a common fault that it is closed.