Alias_deferred* alias options

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Alias options: alias_deferred (ISO 8601 P time duration string), alias_deferred_list (filepath or MTA URL), alias_deferred_mapping (MTA mapping name)

The alias_deferred alias option may be used to add a Deferred-delivery: header line. The value should be a date and time, in ISO 8601 P format.

The alias_deferred_list alias option takes two values, a file specification for a file containing a list of originator addresses (or a URL returning a list of originator addresses) to whose postings to add a Deferred-delivery: header, and the deferral date/time in ISO 8601 format.

As of 8.0 (in prior versions, this feature "existed" but was not working), the alias_deferred_mapping alias option may be used to specify a mapping table through which to run originator addresses. The alias_deferred_mapping alias option takes one or two arguments, with a space between if the optional second argument is included. The first argument is required and must contain at a minimum the name of an MTA mapping table; the first argument may also, optionally, include a vertical bar followed by a string to use as a prefix in the mapping table probe, prior to the originator address. The second argument is optional, consisting of a deferral date/time in ISO 8601 format.

mapping-name[|probe-prefix] ISO-8601-deferral-time

Originator addresses will will be run through the specified mapping. If the mapping template does not begin with an N, n, F, or f, and if it contains a valid date/time specification in ISO 8601 format, then that date/time will be used as a deferral time. If the mapping template does not contain a date/time specification yet does not begin with N, n, F, or f, then the deferral date/time specified as the second argument to alias_deferred_mapping will be used. The default, if no mapping entry matches, or if an entry that begins with an N, n, F, or f matches, is not to add a Deferred-delivery: header.

Note that the intended purpose of a probe-prefix is for convenience in using a single MTA mapping table for multiple mailing list deferral settings, e.g., by using a probe prefix consisting of the list name, so that entries in the mapping table may be list specific. Similarly, a deferral time specified as the second argument permits a default deferral time, that may then be overridden in the case of specific originators in the mapping table result.

Setting bit 3/value 8 of the include_connectioninfo MTA option will cause additional information to be included in the input probe of the mapping named by alias_deferred_mapping. Thus if a probe-prefix has also been specified, then the probe will take the form:


Note that by default the MTA does not honor Deferred-delivery: headers; see the deferreddestination channel option for a discussion. As a functionally preferable alternative to the Deferred-delivery: header line approach for retaining/deferring messages, see also the SMTP SUBMIT FUTURERELEASE extension.

See also: