debian/rules: Use `git' potty wrapper.
[qmail] / BLURB
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1qmail is a secure, reliable, efficient, simple message transfer agent.
2It is meant as a replacement for the entire sendmail-binmail system on
3typical Internet-connected UNIX hosts.
4
5Secure: Security isn't just a goal, but an absolute requirement. Mail
6delivery is critical for users; it cannot be turned off, so it must be
7completely secure. (This is why I started writing qmail: I was sick of
8the security holes in sendmail and other MTAs.)
9
10Reliable: qmail's straight-paper-path philosophy guarantees that a
11message, once accepted into the system, will never be lost. qmail also
12supports maildir, a new, super-reliable user mailbox format. Maildirs,
13unlike mbox files and mh folders, won't be corrupted if the system
14crashes during delivery. Even better, not only can a user safely read
15his mail over NFS, but any number of NFS clients can deliver mail to him
16at the same time.
17
18Efficient: On a Pentium under BSD/OS, qmail can easily sustain 200000
19local messages per day---that's separate messages injected and delivered
20to mailboxes in a real test! Although remote deliveries are inherently
21limited by the slowness of DNS and SMTP, qmail overlaps 20 simultaneous
22deliveries by default, so it zooms quickly through mailing lists. (This
23is why I finished qmail: I had to get a big mailing list set up.)
24
25Simple: qmail is vastly smaller than any other Internet MTA. Some
26reasons why: (1) Other MTAs have separate forwarding, aliasing, and
27mailing list mechanisms. qmail has one simple forwarding mechanism that
28lets users handle their own mailing lists. (2) Other MTAs offer a
29spectrum of delivery modes, from fast+unsafe to slow+queued. qmail-send
30is instantly triggered by new items in the queue, so the qmail system
31has just one delivery mode: fast+queued. (3) Other MTAs include, in
32effect, a specialized version of inetd that watches the load average.
33qmail's design inherently limits the machine load, so qmail-smtpd can
34safely run from your system's inetd.
35
36Replacement for sendmail: qmail supports host and user masquerading,
37full host hiding, virtual domains, null clients, list-owner rewriting,
38relay control, double-bounce recording, arbitrary RFC 822 address lists,
39cross-host mailing list loop detection, per-recipient checkpointing,
40downed host backoffs, independent message retry schedules, etc. In
41short, it's up to speed on modern MTA features. qmail also includes a
42drop-in ``sendmail'' wrapper so that it will be used transparently by
43your current UAs.