In addition to calling a phone number in Gmail, you can also receive calls if you have a Google Voice account. If you already have a Google Voice account, it must use the same username as the Gmail account you wish to receive calls in. If you aren't a Google Voice user, yet, you can upgrade for free if you are in the United States.
To receive calls in Gmail:
- Make at least one outbound call from Gmail.
- In Google Voice, navigate to Settings under the gear icon.
- In the Phones tab, click the check box next to Google Chat.
If you wish to edit the settings for this forwarding phone, click the Edit button. You can disable Gmail as a forwarding phone simply by unchecking the box next to Google Chat.
When you receive a call in Gmail, a call window will appear with a ringtone. If you do not hear the ringtone, please check to make sure your sound is not muted. To accept the call, simply press the Answer button. You can ignore a call by clicking the Ignore button.
You can screen calls you receive in Gmail by clicking the screen button. Doing so will allow you to listen to the caller as they leave you a voicemail. If you wish to interrupt and actually answer the call, simply click the Answer button.
Additionally, once you are on a call you can switch the Google Voice forwarding phone you are using to talk right in the middle of the call by pressing the * key. For example, if you answer your call in Gmail and wish to switch to your cellular forwarding number, pressing * will cause your cellular forwarding phone to ring for you to complete the call.