Login in the server

Follow the below instruction

mtracks#cd /etc/mail/spamassassin/

mtracks#ls -l local.cf

Note down the permission and ownership of the file local.cf

mtracks#vi local.cf

add the line on the file local.cf " blacklist_from          emailid(ex: info@123.com) "

Save the file and try send a mail in that id through telnet and check in the logfile

that in Amavis there will be some score (ex:92.96) given that email id by spam.