I opened a Conpherence thread on my mobile device which I had somehow missed (I guess I didn't see the email). I was trying to work out when the original message was sent, but I couldn't see any timestamp on the original message. When I responded to the message, there was a timestamp (well, technically it only included a date) above my reply.
On the desktop version of Conpherence, I can see the timestamp for the original message on the right hand side.