'properly-sent' originates from the combination of 'properly' and 'sent', where 'properly' means 'in a suitable manner' and 'sent' is the past participle of 'send', meaning 'to cause to go or be taken to a particular destination'.

'properly-sent' evolved from the need to describe the action of sending something in a correct manner, combining the adverb 'properly' with the past participle 'sent'.

Initially, it meant 'sent in a suitable manner', and this meaning has largely remained the same in modern usage.