In all cases where personal card-leaving is not imperative, cards may
be sent either by messenger or by post.
As the former is still regarded by many persons--especially elderly
people--as the only strictly polite medium of transfer, it is
considerate to send cards, invitations, etc., to such people by the
good old-fashioned messenger, rather than to shock unnecessarily a
crystallized sense of propriety by ruthless innovations. But in
general it is more convenient and quite as neat and reliable to send by
post; and the fashion of so doing is now fully adopted by the younger
generation, and no longer subject to criticism.
In stating what _may_ be done, in the way of escaping personal tasks,
we are merely marking the bounds of propriety in one direction. On the
other hand, in most cases, those who choose may make personal calls
instead of those several formal card-leavings. When good form allows
alternatives, each one must judge for himself which form of expression
is most appropriate in any given case. Frank cordiality, amounting to
informality, may be in the best taste in some oases; whereas, in other
instances, only the most conventional and reserved expression of
respect is either agreeable or discreet. In the latter case, let your
card speak _for_ you, and at "long range"--the longer the better.