Rapid worker range pigeon hole shelving units are commonly used in staff rooms as an internal mail system. They come in beech or cherry over ironstone, and have a 5 year commercial use warranty.
Their features include :
The rapid worker pigeon hole units are available in 1 size :
1040 mm high x 1040 mm wide x 380 mm deep.
Summary - All holes are pre threaded & drilled to make self assembly easy. There are 16 shelves to fit which consumes a fair bit of time. If you don't have a cordless drill, then a phillips head screw driver will still do the job easily, but will double the assembly time required.
Recommendations - Easy to do yourself, if you have the time to assemble.