SMTP Restrictions How to create black list For email-id

By through creating blacklist if we sent mail to specific mail id if it is present blacklist then it will not sent to that end customer. By through creating SMTP restriction we will avoid Spam and unwanted mails. How to avoid Spam mail in red hat Linux RHEL5 we edit file in sendmail.mc file.

Step 1: Rhel5
edit sendmail.mc file
#vim /etc/mail/sendmail.mc
Line no:102
FEATURE(`blacklist_recipients')dnl
Step 2:
add entries in access file
#vim /etc/mail/access
Line no:last
From:root@sys4.rpm.com REJECT
To:root@sys4.rpm.com OK
Connect:sys44 OK
Step 3:
restart the sendmail service
#service sendmail restart
sys4:
Step 4:
add dns entry
#vim /etc/resolv.conf
search rpm.com
nameserver 192.168.0.40
Step 5:
test the restrictions from sys4
#echo “test email “ |mail ­s “sample” ­v root@rpm.com
the email will not send .