Get cheques in the post? (4)

I believe the answer is:

earn

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'get' is the definition.
(I know that earn is a more specific form of the action get)

I can't explain the remainder of the clue.

(Other definitions for earn that I've seen before include "Pull in" , "Bring home" , "Take in bread" , "Deserve, gain" , "There's merit" .)

I've seen this clue in the Evening Standard.

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