Sun Java System Messaging Server 6.3 Administration Guide Object Class Check

If the alias search succeeds, the object class of the entry is checked to make sure it contains an appropriate set of object classes for a user or a group. The possible sets of required object classes for users and groups is normally determined by what schemata are active. This is determined by the local.imta.schematag setting.

Table 9–1 shows the user and group object classes that result from various schematag values.

Table 9–1 Object Classes Resulting from Various schematag Values


User Object Classes 

Group Object Classes 





mailRecipient + nsMessagingServerUser




inetLocalMailRecipient + inetmailgroup

The information in this table, like the rest of schema tag handling, is hard coded. However, there are also two MTA options in the option.dat file, LDAP_USER_OBJECT_CLASSES and LDAP_GROUP_OBJECT_CLASSES, which can be set to specify different sets of object classes for users and groups respectively.

For example, a schema tag setting of ims50,nms41 would be equivalent to the following option settings:

LDAP_USER_OBJECT_CLASSES=inetLocalMailRecipient+inetmailuser, mailRecipient+nsMessagingServerUser

LDAP_GROUP_OBJECT_CLASSES=inetLocalMailRecipient+inetmailgroup, mailGroup

The LDAP result is simply ignored if it does not have a correct set of object classes appropriate for a user or a group. The MTA also determines if it is dealing with a user or a group and saves this information. This saved information will be used repeatedly later.

Note that the object class settings described here are also used to construct an actual LDAP search filter that can be used to check to see that an entry has the right object classes for a user or a group. This filter is accessible through the $K metacharacter. It is also stored internally in the MTA's configuration for use by channel programs and is written to the MTA option file, option.dat, as the LDAP_UG_FILTER option when the command imsimta cnbuild -option is used. This option is only written to the file. The MTA never reads it from the option file.