A system and method for sending encrypted messages to a distribution list
that facilitates the sending of such messages only to individuals or
other entities associated with the distribution list that will be able to
read the message. In one embodiment, the method comprises the steps of:
identifying a distribution list address in a message; determining one or
more member addresses associated with the distribution list address; for
each member address, determining if a public key for a member identified
by the respective member address is available on the computing device;
encrypting the message to each member identified by the one or more
member addresses for which a public key for the respective member is
available on the computing device; sending the encrypted message to the
distribution list address if each of the one or more member addresses
associated with the distribution list identifies a member for which a
public key is available on the computing device; and sending the message
to each of the one or more member addresses that identifies a member for
which a public key is available on the computing device otherwise.