At half fare, ten can be sent (3)
I believe the answer is:
fax
'be sent' is the definition.
I can't judge whether this defines the answer.
'at half fare ten' is the wordplay.
'at' means one lot of letters go next to another.
'half' means to take half the letters.
'ten' becomes 'X' (Roman numeral).
'fare' halved is 'fa'.
'fa'+'x' is 'FAX'.
'can' is the link.
Can you help me to learn more?
(Other definitions for fax that I've seen before include "Means of communication" , "Transmission of exact copies of documents electronically" , "Electronic transmission" , "Transmit document" , "Modern method of transmitting printed matter by phone" .)