Section mail - Debian Package: sendmail

 Sendmail is an alternative Mail Transport Agent (MTA) for Debian.
 It is suitable for handling sophisticated mail configurations,
 although this means that its configuration can also be complex.
 Fortunately, easy thing can be done easily, and complex things
 are possible, even if not easily understood ;)  Sendmail is the *ONLY*
 MTA with a Turing complete language under the covers !
 .
 Sendmail provides Security and SPAM/UCE/UBE protection via several means:
  - STARTTLS(SSL) RFC2487 encryption for mail reception/delivery.
  - STARTTLS(SSL) authentication (certificate based) for access/relay control.
  - SMTP AUTH (SASL/PAM) authentication for access/relay control.
  - ACCESS database (by IP/host) for access/relay control.
  - Use of varied Realtime Blackhole Lists (RBL) to prevent access.
  - Integration of LOGCHECK rules to fine-tune logging.
  - Inboard POSIX Regular Expression processing of *all* headers.
  - Ability (via MILTER) to scan/change headers *and* body of *ALL* mail
    A site may utilize zero, one, or more MILTERs.
  - Reduced SUID exposures by running SGID smmsp/mail where possible.
 .
 Sendmail provides Performance and Scalability by:
  - Allowing multiple queues, with the ability to tune both interval and
    queue runners on a queue by queue basis.
  - Providing (a Debian exclusive) an easy to configure means of queue-aging
    to improve throughput by not continually retrying failed deliveries.
  - Allowing most all maps/databases to be obtained via LDAP; reducing the
    number of used databases and simplifying the maintenance of Sendmail.
  - Reducing the file I/O where possible by buffering files in memory.
 .
 Sendmail provides site enhanced site configuration/customization by:
  - Allowing the listener (usually port 25) to run as a daemon or via INETD.
  - Allowing the queue runner (mail delivery) to run as a daemon or via CRON.
  - Automagically updating configuration and databases on upgrades.
  - Providing a Turing complete language for site customization of mail
    handling.
  - Providing a means (MILTER) for a site to scan/change all email - both
    incoming and outgoing.  A site can write their own MILTER, or may use
    any of those found on internet.  To write your own MILTER, you'll need
    to install the optional milter-dev package.
  - Providing extensive documentation via the sendmail-doc (optional) package.
  - Providing an inboard Mail Delivery Agent (MDA) (mail.local), but supporting
    procmail, mailagent, maildrop, or deliver automatically if installed.
    Sendmail will also deliver to anythings else (cyrus, etc) if asked to.
 .
 Sendmail includes *no* Mail User Agents (MUA), you'll have to
 pick from the plethora of available MUAs (pine, mutt, vm, etc.)
 .
 This package supports REGEX, DB, NIS, NIS+, LDAP, DNS, HESIOD maps,
 and has enabled TCPWrappers, IPv6, LockFile, SMTP AUTH(SASL), STARTTLS(SSL).