The English term "post-paid, stamped" matches the Dutch term "gefrankeerd"

other english words that include "paid" : dutch :
paid-up kiet
stamped, post-paid portvrij
paid-up quitte
post-paid, stamped vrachtvrij
other english words that include "stamped" : dutch :
stamped, post-paid portvrij
post-paid, stamped vrachtvrij