Mailed nets off (4)
I believe the answer is:
sent
'mailed' is the definition.
('send' can be a synonym of 'mail')
'nets off' is the wordplay.
'off' indicates an anagram.
'nets' anagrammed gives 'SENT'.
(Other definitions for sent that I've seen before include "Caused to go somewhere" , "Dispatched" , "Told to go - enthralled" , "old money in Tallinn" , "Despatched" .)