HP-UX Mailing Services Administrator's Guide

Configuring and Administering Sendmail
Configuring Sendmail to Reject Unsolicited Mail
Chapter 2 87
• Accept Unqualified Senders
• Blacklist Recipients
• Realtime Blackhole List
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:
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
badlocaluser 550 Mailbox disabled for this username
host.mydomain.com 550 That host does not accept mail
[e-mail] 550 Mailbox disabled for this recipient