Sieve Filter Support

Messaging Server filters are based on the Sieve filtering language, Draft 9 of the Sieve Internet Draft. See RFC3028 for more information about Sieve syntax and semantics. In addition, Messaging Server also supports the following Sieve extensions:

• jettison. Similar to discard in that it causes messages to be silently discarded, but unlike discard, which does nothing but cancel the implicit keep, jettison forces a discard to be performed. The behavioral difference is only relevant when multiple Sieve filters are involved. For example, a system level discard can be overridden by a user Sieve filter explicitly specifying keep, whereas a system level jettison will override anything done by a user Sieve.

• Head-of-household Sieve filters. Provides a means by which one user can specify a Sieve filter for another user. Uses two LDAP attributes in a user entry controlled by these MTA options:

  • LDAP_PARENTAL_CONTROLS - Specifies an attribute containing a string value of either Yes or No. Yes means a head of household Sieve is to be applied to this entry, No means no such Sieve is to be applied. No default.

  • LDAP_FILTER_REFERENCE - Specifies an attribute containing a DN pointing to a directory entry where the head of household Sieve can be found. No default.

    The entry containing the head of household Sieve must contain two attributes specified by the following MTA options:

  • LDAP_HOH_FILTER - Specifies an attribute containing the head of household Sieve. The value of this option defaults to mailSieveRuleSource.

  • LDAP_HOH_OWNER - Specifies an attribute containing the email address of the owner of the head of household. The value of this option defaults to mail.

    Both of these attributes must be present for the head of household Sieve to work.