Dovecot/deliver

About
When invoked with improper options, deliver emits the following: Usage: deliver [-c ] [-a ] [-d ] [-p ] [-f ] [-m ] [-n] [-s] [-e] [-k]

Options
There is some documentation for this command on the Dovecot wiki, but it does not describe the available options.
 * -a address:
 * -c config_file:
 * -d username: (required)
 * -e:
 * -f envelope_sender_address:
 * -k:
 * -m mailbox:
 * -n:
 * -p path:
 * -s:

Usage
This command is used by Postfix for delivering mail to user mailboxes.