Internet Services Delta Manual for HP-UX 11i Version 1.6

• dnsbl
This new DNS-based black list option replaces 'rbl', the RealtimeBlackhole List feature that
was included in Sendmail 8.9.3 release. The rbl option is deprecated now. The dnsbl option
avoids the possible confusion between RealtimeBlackhole List and other DNS-based Blacklist
servers like ORBS. It takes the name of the Blacklist server and also an optional rejection
message as arguments.
dnsbl can be included multiple times in the sendmail.cf file, thereby allowing sites to subscribe
to multiple Blacklist servers. The Blacklist server verifies the IP address of the incoming
connection and rejects all the SMTP commands if the address is blacklisted. An error message
is also displayed.
• delay_checks
This option delays the anti-spam checks by Sendmail until it issues the SMTP RCPT command.
Mails from certain addresses that might have been blocked by other anti-spam checks are
received. In these cases, deferred checks are not done.
By using delay_checks, the rulesets check_mail and check_relay will not be called when
a client connects or issues a MAIL command, respectively. Instead, those rulesets will be called
by the check_rcpt ruleset; they will be skipped if a sender has been authenticated using a
"trusted" mechanism, i.e. one that is defined via the list of AuthMechanisms. If check_mail
returns an error, the RCPT TO command will be rejected with that error. If it returns some
other result starting with $#, then check_relay will be skipped. If the sender address (or a part
of it) is listed in the access map and it has a RHS of OK or RELAY, then check_relay will be
skipped.
• relay_mail_from
This option can be used to facilitate relaying through a user's machine. The sender's name
which is listed as "RELAY" in the access map (tagged with From:) can be specified using this
option. The domain portion of the mail sender is also checked, when the optional argument
'domain' is provided.
• ldap_routing
This option can be used to implement the ldap-based email recipient routing. This provides a
method for re-routing addresses with a domain portion in class {LdapRoute} to either a different
mail host or to a different address.
NOTE: For more information, refer to "LDAP-based Routing" section.
• no_default_msa
This option can be used to generate the configuration file without 'DaemonPortOptions' option
for Message Submission Agent (MSA) daemon. The sendmail.cf configuration file will not
contain the following line:
O DaemonPortOptions=Port=587,
Name=MSA, M=E
• receive_only
This option generates a sendmail.cf file with a new set of rules called 'check_compat'. You
can only receive mail messages, but cannot send them. Two new flags have been added in
the /etc/rc.config.d/mailservs file. They are:
1. SENDMAIL_RECVONLY
This flag must be set to '1' in order to use "receive_only" feature.
2. SENDMAIL_SENDONLY
This flag may not be set to any value.
Chapter Overview 9