They send out the bills (7)
I believe the answer is:
posters
'bills' is the definition.
('poster' can be a synonym of 'bill')
'they send out' is the wordplay.
I cannot quite see how this works, but
'send' could be 'post' (to send in the post) and 'post' is found in the answer.
The remaining letters 'ers' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'the' acts as a link.
Can you help me to learn more?
(Other definitions for posters that I've seen before include "Placards, notices" , "Bills or placards on walls" , "Public placards" , "Contributors to forum" .)