The most common and most likely answer to this crossword clue is the 8 letter word MAILSHOT
I've seen this crossword clue in The Guardian
M
A
I
L
S
H
O
T
More clues leading to the result MAILSHOT
- Suffers hard in test for promotion
- Round of leaflets ending in porch and I almost exploded!
- Slight upset about article on recent leaflet
- Middle of this almost round, circular
- Major post in advertising business
- Report of man wounded in something through the letter box?
- Sort of advertising ruined by defensive armour
- Newspaper’s stolen commercial literature
- Posts stolen unwanted advertisement materials
Buddy explains!

The straight part
We know that "Round of leaflets" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case round of leaflets = mailshot.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 MAILSHOT mean?
MAILSHOT noun- Bulk advertising sent through the post/mail.
- To send bulk advertising to (somebody) in the post.