Internet Express for Tru64 UNIX Version 6.8 Administration Guide (14233)

• In the Relaying Domains List field, specify the list of domain names or IP addresses, to and
from which your Sendmail server is allowed to transmit messages. Separate entries in this
field with blank spaces.
• If you have a file containing the domain names and IP addresses to which you want to
restrict relaying, enter the full pathname for the file in the Relaying Domains File field.
• Set the Allow Relaying from Any Host in Local Domain checkbox to allow any host in your
domain to relay. By default, only hosts listed as OK in the accessdb database are allowed to
relay messages.
• Set the Allow Relaying Based on Sender's MX Records checkbox to permit your server to
relay messages from senders who list your server in their MX records. The MX record consists
of lists of hosts that can accept messages for the specified destination. For example, if your
server received a message from [e-mail] and domain.com lists your server in
its MX records, your server accepts the message.
• Set the Exclude Subdomains from Relaying checkbox to restrict relaying to specific host
names (rather than permit relaying based on subdomain). Usually, relaying is based on
domain names. The names listed as RELAY in the accessdb file and entries in the Relaying
Domains List field (or contained in the Relaying Domains File) are domain names. If you
specify, for example, that example.com is a relaying domain, then messages to and from
example.com, abc.example.com, user.dept.xyz.example.com are all accepted for
relaying. When the Exclude Subdomains from Relaying checkbox is set, Sendmail looks up
individual host names before determining whether or not to relay a message.
• Set the Allow Relaying from Local Host checkbox to relay a message when the sender's
return path domain (for example, MAIL FROM: <[e-mail]>) is a local domain.
• Under normal behavior, if a message header lists a recipient as user%site@anothersite
and anothersite is included in the Relaying Domains list (or Relaying Domains file),
Sendmail strips @anothersite and rechecks user@site for relaying. Set the Disable
Checks For Relay Forwarding checkbox to prevent this behavior.
Note:
Setting this checkbox may allow spam mail to relay through your server if it is not set up
properly.
• Set the Check for Blacklist Recipients in Access Database checkbox when you want to block
incoming mail for certain recipient user names, host names, or IP addresses. For example,
you can block incoming mail addressed to nobody, host example1.domain.name, or
user [e-mail], as specified in the accessdb file. (See
Section 5.1.4.6.2: Configuring the Access Database for information on the accessdb file.)
• Set the Allow Unrestricted Relaying checkbox, to accept mail from outside your domain
and send it to another host outside your domain. When this checkbox is set, your site will
allow mail relaying from any site to any site.
• Set the Reject Mail from Server in Realtime Blackhole List checkbox to reject mail from any
server listed in the Realtime Blackhole List. For more information on the Mail Abuse
Protection System (MAPS) and the Realtime Blackhole List, see
http://mail-abuse.org/rbl/
When you are through setting the Configure Relaying options, click on Submit. A success message
confirms that relaying has been configured on your system and that your Sendmail server has
been restarted.
5.1.4.6.2 Configuring the Access Database
The Sendmail server uses an access database for the following purposes:
5.1 Sendmail Server Administration 107