Yes, but this really is an issue that depends entirely on the computer and modem hardware. When a computer is in sleep mode, and an incoming call occurs, the modem hardware is actually responsible for “waking” up the computer. This is commonly referred to as a “Wake on Ring” feature. Once the computer has been told to “wake up” by the modem hardware, the FaxTalk software will be waiting for the modem to report the incoming call and will answer the phone accordingly. You should check with your modem or computer manufacturer to determine if your modem supports “Wake on Ring” when in sleep mode.