text: There may have been one, have a look at this:  
  
  https://osm.mathmos.net/postboxes/boxinfo.cgi?ref=SM1+295
  
  
  This is from a list released by Royal Mail as part of a Freedom of Information request. 
  
  In addition there is also a map that was created on the same information where you can find SM1 295
  
  http://dracos.co.uk/made/nearest-postbox/#