Take exception to being mailed again (6)
I believe the answer is:
resent
I believe this clue is a double definition.
'take exception to' is the first definition.
(I've seen this in another clue)
'mailed again' is the second definition.
('sent' can be a synonym for 'mailed' so perhaps 'resent' is OK for 'mailed again')
'being' is the link.
(Other definitions for resent that I've seen before include "Object to" , "grudge" , "Dispatched again - take amiss" , "being put in post again" , "Feel aggrieved at" .)