Polycom 400 User Manual page 76

4. If the called party does not answer, you can do one of the
following:
•
Press the line button which has the held call to cancel the
transfer and return to the holding party, or
•
Hang up and let the call transfer to the called party's voice
mail.
Polycom Telephone User Guide
621-00000092
VocalData Telephone Features 69