If an answering machine is connected, make sure the product's Rings to Answer setting is set higher than the number of rings your answering machine is set to answer a call. For example, if the answering machine is set to pick up on the fourth ring, set the product to pick up on the fifth ring or later.
If a telephone is connected, and you use it to answer a call that turns out to be a fax, wait until the product's LCD screen displays a message that a connection has been made before hanging up.