建立 /etc/postfix/reject_user, 填入要封鎖的帳號資料, 建立該db檔.
smtpd_recipient_restrictions = check_sender_access hash:/etc/postfix/reject_user,
permit_mynetworks,
permit_sasl_authenticated,
reject_rbl_client cbl.abuseat.org,
reject_rbl_client list.dsbl.org,
reject_rbl_client sbl.spamhaus.org,
reject_rbl_client pbl.spamhaus.org,
reject_rbl_client bl.spamcop.net,
reject_rbl_client cblless.anti-spam.org.cn,
reject_rbl_client psbl.surriel.com,
reject_rbl_client bl.spamcop.net,
reject_unknown_sender_domain,
reject_unknown_recipient_domain,
reject_unauth_destination,
reject_invalid_hostname,
reject_non_fqdn_hostname,
reject_non_fqdn_sender,
reject_non_fqdn_recipient,
smtpd_sender_restrictions = check_sender_access hash:/etc/postfix/reject_user,
permit_mynetworks,
reject_unknown_client,
reject_unknown_sender_domain,
reject_invalid_hostname,
reject_non_fqdn_hostname,
reject_non_fqdn_sender
2. vi /etc/postfix/reject_user
user@test.xxx.com.tw REJECT
user1@test.xxx.com.tw REJECT
#DISCARD 直接丟棄
postmap /etc/postfix/reject_user
service postfix restart