The message's envelope recipient is local@domain. qmail-local records local@domain in a new Delivered-To header field. If exactly the same Delivered-To: local@domain already appears in the header, qmail-local bounces the message, to prevent mail forwarding loops.
The message's envelope sender is sender. qmail-local records sender in a new Return-Path header field.
homedir is the user's home directory. It must be an absolute directory name.
dash and ext identify the .qmaildashext file used by qmail-local; see dot-qmail(5) . Normally dash is either empty or a lone hyphen. If it is empty, qmail-local treats a nonexistent .qmailext the same way as an empty .qmailext: namely, following the delivery instructions in aliasempty.
The standard input for qmail-local must be a seekable file, so that qmail-local can read it more than once.