Neither posted nor moved? (6)
I believe the answer is:
unsent
'neither posted nor moved?' is the definition.
(sent can mean posted or moved)
'nor moved?' is the wordplay.
'nor' becomes 'un' (I can't explain this - if you can you should give a lot more credence to this answer).
'moved?' becomes 'sent' (sending is a kind of moving).
'un'+'sent'='UNSENT'
(Other definitions for unsent that I've seen before include "not transmitted" , "Not dispatched" .)