Qmail configuration lookup module
None, only operates as a lookup module.
This module uses the standard qmail configuration files to determine if an address is valid, using the same lookups that qmail would. It first checks control/locals and then control/virtualdomains to determine if the domain is valid, and to determine the prefix to add to virtual domain usernames. It then looks up the resulting username in users/cdb (or the system password table if the CDB does not exist) to determine the correct home directory. If the address would require a .qmail-something file, it ensures that that file exists as well, doing -default checks as necessary.
If this is set and the domain name is not a local or virtual qmail domain, this domain name is substituted and the lookup succeeds. This allows for setups where domains listed in control/rcpthosts and control/morercpthosts.cdb (which are accepted by the SMTP receiver) are not listed as local or virtual domains. If this is set to an empty value, "localhost" is substituted.
When missing domain substitution is being done, the value of this variable is used to replace the username. The value must exist as a valid system user. Defaults to "alias" which will normally exist on all qmail systems.
The root directory under which all the qmail configuration files are expected to be found. Defaults to "/var/qmail", which is the normal qmail install path.