Dealing with story about case of ageism upset correspondent (7)
I believe the answer is:
emailer
'correspondent' is the definition.
I know nothing about this answer so I cannot judge whether this works.
'dealing with story about case of ageism upset' is the wordplay.
'dealing with' becomes 're' (regarding).
'story' becomes 'lie' (story can mean a fabrication).
'about' is an insertion indicator.
'case of' says to hollow out the word (remove centre letters) (outsides of).
'upset' says the letters should be written in reverse.
'ageism' with its middle removed is 'am'.
're'+'lie'='relie'
'relie' going around 'am' is 'reliame'.
'reliame' reversed gives 'EMAILER'.
Can you help me to learn more?
(Other definitions for emailer that I've seen before include "man of letters for the modern age?" , "Sender of electronic messages" .)