One contacting English and American author (7)
I believe the answer is:
emailer
'one contacting' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.
'english and american author' is the wordplay.
'english' becomes 'E' (abbreviation).
'and' means one lot of letters go next to another.
'american author' becomes 'Mailer' (Norman Mailer, 1923-2007).
'e'+'mailer'='EMAILER'
Can you help me to learn more?
(Other definitions for emailer that I've seen before include "Sender of electronic messages" , "man of letters for the modern age?" .)