Postfix is Wietse Venema's mail transport agent that started life as an
alternative to the widely-used Sendmail program. Postfix attempts to
be fast, easy to administer, and secure, while at the same time being
sendmail compatible enough to not upset existing users. Thus, the outside
has a sendmail-ish flavor, but the inside is completely different.
There are some significant differences between the Debian Postfix packages,
and the source from upstream:
1. The Debian install is chrooted by default.
2. Dynamically loadable map support.
3. For policy reasons:
a. SASL configuration goes in /etc/postfix/sasl
b. myhostname=/path/to/file is supported (and used) in main.cf
4. IPV6 support is enabled: postfix listens on ipv6/ipv4 by default,
postfix (2.4-20070123-1) experimental; urgency=low
As of this version, Debian's postfix defaults to matching upstream
behavior (introduced in postfix 2.0) in handling excessively long lines
in a message:
The Postfix SMTP client now breaks message header or body lines that
are longer than $smtp_line_length_limit characters (default: 990).
Earlier Postfix versions broke lines at