[interestingly the link goes to a directory with previous and beta
versions of sendmail, so the move to commercialism coincides with the move
to the new vapourware releases]
Tools for Spam Control
The spam control features in 8.9 fall into two areas: repackaging of
features that already existed in 8.8 but were difficult to configure
and totally new features.
Configuration Changes
Promiscuous relaying is turned off by default.
Disallow mail having an invalid host name in the return address by
default.
By default, disallow acceptance of mail from any sender that has
does not have a fully qualified domain name.
FEATURE(relay_entire_domain) to allow relaying within your domain.
Optional access control database allowing rejection of mail from
specific domains.
FEATURE(rbl) to enable use of the Realtime Blackhole List
maintained at rbl.maps.vix.com.
[hmm... haven't I seen these in another mailer....]
New Features
Regular expression matching on addresses (e.g., all-numeric user
names can be rejected).
MaxRecipientsPerMessage option, to restrict large amounts of
messages being sent at one time to multiple
users (a common characteristic of spam).
Feature to extract all MX records for a given domain; this allows a
site to allow relaying only for hosts for which
they a valid MX server.
Distinguish between temporary and permanent map lookup failures.
This allows better rejection of SMTP
envelope senders that have invalid host names.
Allow message rejection on the basis of header contents. For
example, messages with invalid Message-Id:
headers or a "To: friend@???" header can be rejected.
Limit the size of HELO/EHLO parameter to prevent spammers from
hiding their connection information in
Received: headers.
New builtin "discard" mailer to allow messages to be accepted and
then dropped.
[... yes - definitely seen this before!]
[what is that about limiting the HELO parameter??]
All this and more can be found at
http://www.sendmail.com/
Nigel.
--
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