Calling
An alternate to emailing a friend is to call and talk to them. It is possible to communicate with other mail users from the call pad that support the SIP.
The call pad also supports instant text messaging. Type in a message in the input box and press the Send button.
Pressing the microphone button 
will toggle the mute state of the microphone. Similarly pressing the speaker button will silence the speaker. Press these buttons if you only want to send instant messages.
The configuration button 
allows options to be set. Call Options sets what is recorded to the call history. SIP registration is used to configure a SIP provider to be able to make external phone calls.