11.2 qmail-remote

As we saw in Chapter 2, the main qmail-send daemon passes remote deliveries to qmail-rspawn, which runs qmail-remote to attempt each delivery. The arguments to qmail-remote are the remote hostname, the envelope sender, and the envelope recipients, with the message to send on its standard input. Within qmail, qmail-remote is always run with a single recipient, and the host is the domain part of the recipient address. Other applications can use qmail-remote as a simple mail sending application, with as many recipients per message as desired.

Once qmail-remote has attempted delivery, it writes recipient report(s) and a message report to its standard output. The format of the reports is documented in the qmail-remote manpage.