s/qmail - overview of s/qmail documentation
s/qmail is a secure, encrypting, authenticating, reliable, efficient, yet simple IPv4/IPv6 message transfer agent based on qmail and ought to be plug-in compatible. The s/qmail software includes Dan Bernstein’s fastforward and qmailanalog package in addition with other enhancements taken mainly from the Spamcontrol patch.
The current version of s/qmail depends on the fehQlibs and OpenSSL or LibreSSL.
Users who want to control incoming messages should read dot-qmail(5). Available commands for the .qmail file include qbiff(1), qreceipt(1), forward(1), fastforward(1), bouncesaying(1), and condredirect(1). Other helpful commands include maildirmake(1), maildir2mbox(1), and maildirwatch(1).
System administrators who want to control the entire s/qmail system should start with qmail-control(5), qmail-mfrules(8), and qmail-start(8).
There are four queue-monitoring/mangement tools: qmail-qread(8), qmail-qstat(8), qmail-qmaint(8), and qmail-tcpto(8). qmail-mrtg(8) allows to feed the s/qmail logs to MRTG. Incoming SMTP connections are handled by qmail-smtpd(8) and qmail-recipients(8) optionally together with qmail-smtpam(8), qmail-authuser(8) and perhaps with qmail-vmailusers(8) if virtual mail managers like vpopmail or vmailmgr are in use.
SRS is availalable within s/qmail by means of the additional commands srsforward(1) and srsreverse(1). DKIM message signing and verification is achieved with qmail-dksign (8) and qmail-dkverify(8).
s/qmail offers two command-line message-sending interfaces: qmail-inject(8) and mailsubj(1). For background information on Internet mail messages, see addresses(5), envelopes(5), qmail-header(5), and forgeries(7).
Miscellaneous documentation includes qmail-limits(7) and qmail-pop3d(8).
Apart from the Internet mail message transport protocols ESMTP/ESMTPS s/qmail supports QMTP/QMTPS together with the Pop Office message protocols POP3/POP3S depending on the ucspi-ssl package for TLS support.
This documentation describes version 4.3.20 of s/qmail. See https://www.fehcom.de/djbware.html for other s/qmail-related software.