Originally Posted by Szat
Wow, there's no mute feature? Mute has been on phones since touch tones came around!
There is a mute feature. I know this because I own the phone.
What he asked for was "hold", which yes mute it's like hold but is not the same.
What you can try, is to "switch to the other line" by pressing the send button with out dialing any numbers.
This would normally start 3 way calling but since you did not dial a number to call it should or used to put your caller on a hold.
I have not tried this with the env3 but with my old phone this used to work.