HP-UX Mailing Services Administrator's Guide (B2355-91064)

Accept Unresolvable Domains
This feature enables Sendmail to accept all MAIL FROM: parameters that are not fully
qualified, for example, a mail message whose host part of the argument to the MAIL
FROM: parameter cannot be located in the host name service, such as DNS.
Accept Unqualified Senders
This feature allows you to accept all mail where the sender’s mail address does not
include a domain name.
Normally, the MAIL FROM: commands in the SMTP session are refused if the connection
is a network connection and the sender address does not include a domain name.
Blacklist Recipients
This feature enables Sendmail to block incoming mail messages destined for certain
recipient user names, host names, or addresses. This feature also restricts you from
sending mail messages to addresses with an error message or REJECT value in the
Access Database file.
Example 1
For example, given the following entries in the Access Database file:
550 Mailbox disabled for this usernamebadlocaluser
550 That host does not accept mailhost.mydomain.com
550 Mailbox disabled for this [e-mail]
Recipient of [e-mail], any user at host.mydomain.com,
and the single address [e-mail] will not receive mail.
Example 2
[e-mail] REJECT
cyberspammer.com REJECT
Mail cannot be sent to [e-mail] or to anyone at cyberspammer.com.
Realtime Blackhole List
This feature rejects hosts listed in the Realtime Blackhole List, which is found in the
Realtime Blackhole List server. The server is blackholes.mail-abuse.org.To use
this feature, you must add the following line to the DNS database:
1.5.5.192.blackholes.mail-abuse.org IN A 127.0.0.2
You can specify the Realtime Blackhole List servers in the sendmail.cf file.
88 Configuring and Administering Sendmail