Sendmail spam filtering rules
HOW TO use Sendmail Spam Control
Mail must originate or terminate locally
(on this host), with exceptions made for
hosts listed, one per line, in
/etc/sendmail.cR. (In this incarnation,
this ruleset does not allow relaying
within your domain, except for the hosts
listed in /etc/sendmail.cR. Note
carefully, you must list fully qualified
host names for each host you wish to
allow relaying. Simply listing a domain
name is not enough. Ideally, for
Sendmail spam control it would only
restrict relaying from outside your
domain. This is particularly useful if
you are using mail clients such as MH or
Eudora that like to try to find an SMTP
relay on the local network to do
outgoing mail submission.)
In order for Sendmail Spam Control
to install : Insist On Valid Host Name
In MAIL FROM: Command
You want to reject mail that has bogus
host names in the MAIL FROM: SMTP
command. (Also includes the previous
fix, but modified so that it will
deliver an insulting message back to the
perpetrators.)
Check for validity in the MAIL command.
In this case you have to permit people
in the spammers database greater access
to your server (e.g., they will be able
to use VRFY and EXPN), but you can still
prevent them from sending mail.
This ruleset is incompatible with the
DeliveryMode=defer option, since it
requires that a DNS lookup be done
immediately upon mail receipt. |
