Sendmail with DNSBL enhdnsbl Whitelist

How to enable DNSBL, enhdnsbl Barracuda configuration in Sendmail, Enable Domain Black List and white list.

Sendmail with DNSBL

Domain Name System Blacklists, also known as DNSBL’s or DNS Blacklists, are spam blocking lists that allow a website administrator to block messages from specific systems that have a history of sending spam.
To enable external DSN based blacklist feature on your sendmail server, you can add the below mentioned configuration in the file located in /etc/mail . Below I have mentioned eight dnsbl configurations, You can choose the black list based on your environment, server load etc and add it .
#vim /etc/mail/

FEATURE(`enhdnsbl', `', `"Spam blocked see:"$&{client_addr}', `t')
FEATURE(dnsbl,`',`Message from $&{client_addr} rejected - see$&{client_addr}')
FEATURE(rhsbl,`',`"550 Mail from domain " $`'&{RHS} " refused. MX of domain do not accept bounces. This violates RFC 821/2505/2821 - see"')
FEATURE(`dnsbl', `', `"Rejected due to Spamhaus listing see" $&{clientaddr} " for more information"')

Restart the sendmail service
#service sendmail restart

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