Domain match url MTA option

Direct LDAP domain lookup URL
The  option may be used to specify an additional, special lookup to perform when looking for domains during a   rewrite rule template LDAP  lookup; (that is, a  lookup in addition to the regular lookup for normal domains triggered by $V). This additional lookup will be performed only if the check for a normal, hosted domain fails. The main use of this option is to enable use of vanity domains, vanity domain being disabled by default. To enable the use of vanity domains, in Schema 1 mode set domain_match_url=ldap:///$B?msgVanityDomain?sub?(msgVanityDomain=$D) Note that use of vanity domains is NOT RECOMMENDED!

See also:
 * Direct LDAP domain lookup MTA options
 * Aliases in LDAP