Per client/helo/sender/recipient UCE restrictions ================================================= The Postfix SMTP server allows you to specify UCE restrictions on the right-hand side of SMTPD access tables, so that you can have different UCE restrictions for different clients or users. The only anomalies in this scheme are that (1) message header checks are still the same for every message, and (2) you must use a restriction class name (see below) if you want to specify a lookup table on the right-hand side of an access table (this is because Postfix needs to open those tables ahead of time). Restriction classes allow you to give easy-to-remember names to groups of UCE restrictions (such as permissive, restrictive, and so on). For example in main.cf: smtpd_restriction_classes = restrictive, permissive restrictive = reject_unknown_sender reject_unknown_client ... permissive = permit With this in place, you can use "restrictive" or "permissive" on the right-hand side of your per-client/helo/sender/recipient SMTPD access tables.