The most common and most likely answer to this crossword clue is the 7 letter word NOTELET
I've seen this crossword clue in The Times
N
O
T
E
L
E
T
More clues leading to the result NOTELET
- Brief message backing TV fundraiser Henry’s left
- Forbidden to hold onto European correspondent’s material
- Short letter to reveal upset over film
- Folded card husband lost in TV fundraiser turned up
- On which to jot thanks that TV fundraiser returned minus original host!
- TV fundraiser given up after husband left memo
- Brief letter allowed, supporting climbing school
- Short message about lengthy transmission husband dropped
- Brief communication raising school rent
- Communication when school rejected sanction
Buddy explains!

The straight part
We know that "correspondent’s material" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case correspondent’s material = notelet.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does NOTELET mean?
NOTELET noun- A brief letter or note; a billet.
- A notecard; a small folded sheet of notepaper, often with a decorative design on the front, intended for a short letter or note.