Something sent round (8)
I believe the answer is:
circular
I believe this is a double definition.
'something sent' is the first definition.
(type of posted communication)
'round' is the second definition.
(I know that round can be written as circular)
(Other definitions for circular that I've seen before include "plug, perhaps" , "One sort of saw" , "such unconvincing reasoning" , "Widely-distributed notice" , "Perfectly round" .)