Poet gets post but not a great deal (6)
I believe the answer is:
milton
'poet' is the definition.
(John Milton)
'post but not a great deal' is the wordplay.
'post' becomes 'mail' (synonyms).
'but not' suggests deleting specific letters.
'great deal' becomes 'ton' (both can mean a large amount).
'mail' with 'a' removed is 'mil'.
'mil'+'ton'='MILTON'
'gets' acts as a link.
(Other definitions for milton that I've seen before include "Comus poet" , "Great poet of 'Paradise Lost'" , "English epic poet" , "Blind poet of ` `Paradise Lost' '" , "Bucks new town" .)