Deferredsource, nodeferredsource, deferreddestinction, nodeferreddestination Channel Options

Deferred delivery dates
The  and   channel options implement recognition and honoring of the Deferred-delivery: header. These options are newly implemented in the 7.0 release of Messaging Server. When set on a source or destination channel respectively, messages with a deferred delivery date in the future will be held in that channel queue until the deferred delivery date is reached. See RFC 2156 for details on the format and operation of the Deferred-delivery: header line. Both channel options accept a single integer argument specifying the maximum number of seconds in the future a Deferred-delivery: date value can specify and still be honored. If both options apply to a transaction the lower of the two limits will apply. The integer arguments are optional in a traditional  file - if the value is omitted a default of 60&#x2a;60&#x2a;24&#x2a;7 (7 days) will be assumed.

Prior to the 7.0 release the  channel option  provides similar functionality to. In 7.0 the MTA accepts  as a synonym for   in the   file; in Unified Configuration,    and   may no longer be used and the preferred   and   must be used instead. Note also that prior to 7.0 deferred delivery was not a reliable service. In particular, deferred handling information does not survive Job Controller restarts.

and  are the defaults. It is important to realize that while support for deferred message processing is mandated by RFC 2156, actual implemention of it effectively lets people use the mail system as an extension of their disk quota.

See also the &#x5b;DEFERRED&#x5d; alias file named parameter and, in Unified Configuration, the   alias option, which provide a per-alias (per-recipient) mechanism to add a Deferred: header line. For users defined in LDAP, the attribute, or whatever attribute is named by the   MTA option, also provides a way to add such a header line.

See also the  channel option, which enables use of the SMTP FUTURERELEASE extension, offering superior functionality over Deferred-delivery: header line based message deferral.

See also:
 * futurerelease Option
 * Alias file named parameters
 * alias_deferred Option
 * ldap_add_header MTA Option
 * Processing control and job submission channel options
 * Channel options