Sendmail 8.9.3 Release Notes

22 Chapter1
New and Changed Features
New Features
accept such domains, use the features discussed below.
— Accept unresolvable domains
Setting this option, will allow accepting of all those MAIL FROM:
parameters that are not fully qualified i.e, if the host part of the
argument to MAIL FROM: command cannot be located in the host
name service (e.g, DNS).
This feature is commented in the default sendmail.cf file. To
enable this feature, use the gen_cf script distributed along with
the sendmail-8.9.3 patch.
— Accept unqualified senders
Setting this option, will allow accepting of all those MAIL FROM:
parameters where the sender’s mail address does not include a
domain name.
Normally, MAIL FROM: commands in the SMTP session will be
refused if the connection is a network connection and the sender
address does not include a domain name.
This feature is commented in the default sendmail.cf file. To
enable this feature, use the gen_cf script distributed along with
the sendmail-8.9.3 patch.
— Black list recipients
Setting this option, will turn ON the ability to block incoming mail
messages destined for certain recipient usernames, hostnames, or
addresses. This feature needs the access db file to be included.
Enabling this feature will also restrict you from sending mail
messages to all those addresses that have an error message or
REJECT as value part in the access db file.
For example,if you have the following entry in theaccess database
file:
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
This would prevent a recipient of [e-mail],
any user at host.mydomain.com, and the single address
[e-mail] from receiving mail.