Ldap domain attr source channel MTA options

Direct LDAP attribute name MTA options:  (LDAP attribute name)
The  MTA option specifies the name of an LDAP attribute used, when the   channel option is in effect, to store the name of an MTA channel to consider as the source channel for messages submitted from users in this domain. See also the   MTA option which names an analogous user-level LDAP attribute. If both a user-level and domain-level attribute are set, the user-level value overrides the domain-level value.

See also:
 * Direct LDAP attribute name MTA options
 * userswitchchannel Option