Complex sentence: The building opened in 2002, with the Royal Mail stating it would save of lorry journeys per year on local roads, however the depot closed in 2004 when the Post Office ceased to use the rail network.
Split into simpler sentences: The building opened in 2002, with the Royal Mail stating it would save of lorry journeys per year on local roads. However, the was depot closed only two years later in 2004, when the Post Office ceased to use the rail network.