The local channel is used to deliver messages to addresses on the local host. On UNIX, the local channel is the l (lowercase "L") channel.
When using a mail user agent on the local system to send mail (to
anywhere), /pmdf/bin/sendmail
is invoked as the
replacement for sendmail to queue the messages to the appropriate
queues, and then the channel programs for those queues will process the
messages. Such local
mail user agents may include mail, mailx, mailtool, Pine, etc.
-- any mail user agent that normally invokes sendmail.
The PMDF configuration utility always generates a local channel.