By such means, send a letter (6)

I believe the answer is:

postal

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'by such' is the definition.
I can't judge whether this defines the answer.

'send a letter' is the wordplay.
'send' becomes 'post' (to send in the post).
'letter' becomes 'l'.
'post'+'a'+'l'='POSTAL'

'means' is the link.

Can you help me to learn more?

(Other definitions for postal that I've seen before include "To do with snail mail" , "To Alps (anag.)" , "Relating to mail delivery" , "Relating to mail service" , "Type of order" .)

I've seen this clue in the Evening Standard.

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