> What is a fastest method to block that recipient domain (because I would > like it not to ask the ldap server for that account/domain )
One way to block an entire domain: main.cf smtpd_recipient_restrictions = check_recipient_access hash:/etc/postfix/block_domains block_domains subdomain.domain.ltd 550 Invalid Recipient Domain You can set "Invalid Recipient Domain" to any error message. And don't forget to run "postmap block_domains"
