The most common and most likely answer to this crossword clue is the 4 letter word MAIL
I've seen this crossword clue in The Daily Telegraph
M
A
I
L
More clues leading to the result MAIL
Buddy explains!
The straight part
We know that "Large number have a complaint when It goes astray" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case large number have a complaint when it goes astray = mail.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 MAIL mean?
MAIL noun- A bag or wallet.
- A bag containing letters to be delivered by post.
- The material conveyed by the postal service.
- A stagecoach, train or ship that delivers such post.
- The postal service or system in general.
- The letters, parcels, etc. delivered to a particular address or person.
- Electronic mail, e-mail: a computer network–based service for sending, storing, and forwarding electronic messages.
- A trunk, box, or bag, in which clothing, etc., may be carried.
- (ditransitive) To send (a letter, parcel, etc.) through the mail.
- (ditransitive) To send by electronic mail.
- To contact (a person) by electronic mail.
- Armour consisting of metal rings or plates linked together.
- A contrivance of interlinked rings, for rubbing off the loose hemp on lines and white cordage.
- Any hard protective covering of an animal, as the scales and plates of reptiles, shell of a lobster, etc.
- A spot on a bird's feather; by extension, a spotted feather.
- To arm with mail.
- To pinion.
- An old French coin worth half a denier.
- A monetary payment or tribute.
- Rent.
- Tax.