Ldap_host_alias_list Option

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Updated in release: 7.0.5.36


The local_host_alias_list option is available at the base and MTA levels. (The MTA normally uses the base level value, unless its own MTA level override value has been set.) The Message Store uses the base level option value. In legacy configuration, the local.imta.hostnamealiases must be used for this purpose.

The value of local_host_alias_list sets additional host names to be interpreted as the "local host" for certain interpretation purposes.

Use with base

The ldap_host_alias_list Base option allows setting a list of host names that will be recognized as synonyms for the host name. It corresponds to the configutil parameter local.imta.hostnamealiases in legacy configuration. The value takes a comma-separated list of up to 40 host aliases; each host alias may be at most 256 characters long; the total length of the entire list is limited to 1024 characters. (In iMS 5.2, the limits were smaller: at most 20 host aliases and each host alias at most 252 characters long.)

In Unified Configuration, this value is used by the Message Store when interpreting the mailHost attribute to determine whether a user's mailboxes can be accessed locally. In legacy configuration, the local.imta.hostnamealiases must be used for this purpose.

Unless mta.local_host_alias_list has been set (thereby overriding the base.local_host_alias_list), the local_host_alias_list base option also affects MTA operation. The ldap_host_alias_list value(s) are used by the MTA when deciding whether a domain's mailRoutingHosts value(s) or a user's mailHost value is "local" (this MTA itself). That is, once an LDAP lookup of a domain or user occurs, this option's value(s) affect the interpretation of the result of the LDAP lookup.


See also:

Use with mta

The ldap_host_alias_list MTA option specifies local host aliases for LDAP lookup result interpretation purposes. Specifying this option at MTA level overrides, for MTA purposes, the base.ldap_host_alias_list base option (local.imta.hostnamealiases configutil parameter in legacy configuration), thereby allowing the MTA to recognize a different set of such aliases than the Message Store recognizes. Neither the base nor MTA level option has a default value; if the base level option is set, it is used by the MTA unless the MTA level option has been explicitly set in which case the MTA uses the MTA level option's value.

The ldap_host_alias_list value takes a comma-separated list of up to 40 host aliases; each host alias may be at most 256 characters long; the total length of the entire list is limited to 1024 characters. (In iMS 5.2, the limits were smaller: at most 20 host aliases and each host alias at most 252 characters long.) New in Messaging Server 7.0.5.36, the MTA supports wild-carded host name values.

The ldap_host_alias_list value(s) are used by the MTA when deciding whether a domain's mailRoutingHosts value(s) or a user's mailHost value is "local" (this MTA itself). That is, once an LDAP lookup of a domain or user occurs, this option's value(s) affect the interpretation of the result of the LDAP lookup.

An important use of the ldap_host_alias_list is in email configurations spanning multiple data centers, with routing via SMTP between data centers and delivery LMTP within each data center. In such a setup the mailbox delivery_options MTA option clause is set for LMTP but is left as mailhost-dependent, rather than as in a typical configuration being marked with "#" to be mailhost-independent. Then all the LMTP hosts for the local data center are listed in the ldap_host_alias_list MTA option value on each MTA. Note that as the number of stores becomes large it's preferable to use a naming convention for stores along with a wildcard ldap_host_alias_list value, to avoid configuration churn as stores are added or deleted.


See also:


See also: