Where, in Italy, mail is sorted for the north (5)
I believe the answer is:
milan
'where in italy' is the definition.
The answer is a location as well as being a singular noun. This is suggested by the definition.
'mail is sorted for the north' is the wordplay.
'is sorted' indicates anagramming the letters.
'for' means one lot of letters go next to another.
'the north' becomes 'N' ('N' can be a synonym of 'north').
'mail' is an anagram of 'mila'.
'mila'+'n'='MILAN'
Can you help me to learn more?
(Other definitions for milan that I've seen before include "Northern Italian city" , "Italian industrial city" , "N. Italian city" , "province" , "European city" .)