Alan Boyd: > Hello, > > I'm trying to find a way to reject email which is sent to an unknown > user (determined by an external program) at a virtual domain, such > that the email doesn't even enter the mail queue.
Wietse Venema: > For Postfix to reject invalid recipients at the SMTP port, this > information must be available as a lookup table. You will have > to use one of the supported database types: file, SQL, LDAP, and > so on, or add your own table lookup mechanism. > > See "man 1 postconf", option "-m". Alan Boyd: > Hi, > > Thanks for the response. Two questions: > > 1) Which variable in main.cf should this lookup table be referenced in? Recipient validation is normally done with the lookup tables listed in http://www.postfix.org/ADDRESS_CLASS_README.html, however you can also use smtpd_***_restrictions to block recipients. > 2) I've read the man page, but it isn't clear in whether I can > reference a database or table which is produced as the output of a > program? For example, whether postfix can read the output of some kind > of generatetable.pl file? The following mechanisms are implemented as lookups from a static file: hash, btree, dbm, cdb, regexp, pcre, cidr. In this case you provide the data in the form of a file, and Postfix will do the lookups from that file. See "man postmap". The following lookups are implemented by sending a query to a running program: mysql, pgsql, ldap, tcp, nis, nisplus (see http://www.postfix.org/mysql_table.5.html etc.); the smtpd policy protocol (http://www.postfix.org/SMTPD_POLICY_README.html); and the Milter protocol (http://www.postfix.org/MILTER_README.html). In this case you provide the running program that answers to Postfix's queries. Wietse
