In
outlook 2013 , when
you reply a message you have to enter your message in the bottom
preview pane.
There
are two options, "Pop out" and "discard".
You
can disable composing in the reading pane using a reg key - the
buttons will open a new window.Option
1:
[HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\15.0\outlook\message]
"disablereadingpanecompose"=dword:00000001
"disablereadingpanecompose"=dword:00000001
Option
2:File->
Options-> Mail-> Replies and Forwards-> Use inline replies
when replying or forwardingIn
RTM this option is :File->
Options-> Mail-> Replies and Forwards-> Open replies and
forwards in a new window