Read column providing special delivery service (10,4)
I believe the answer is:
registered post
'special delivery service' is the definition.
(type of postal service)
'read column' is the wordplay.
'read' becomes 'registered' (register can mean to read).
'column' becomes 'post' (both can mean an upright support).
'registered'+'post'='REGISTERED POST'
'providing' acts as a link.
(Other definitions for registered post that I've seen before include "Special form of delivery" , "Specially secure delivery" , "important letters? - with 28a" , "Type of mail" , "sign for this?" .)