Dispositionchannel, notificationchannel Channel Options

Notification and disposition channels
New in 6.2: By default, the MTA always generates notification messages (Delivery Status Notifications) such as bounce messages, warnings of delayed delivery, etc., and disposition messages (Message Disposition Notifications) such as "vacation" messages, through the  channel. That is, the channel that needs to generate a DSN or MDN submits the DSN or MDN, respectively, to the  channel; and the   channel subsequently enqueues the DSN or MDN on to the appropriate outbound channel (back to the sender of the original message).

The  channel option may be used on a channel to tell it to generate DSNs through the specified channel, rather than through the (default)   channel. It takes a required argument, which is the name of the channel to which to enqueue the newly generated DSNs; normally, this should be some   channel  that a site defines for this purpose.

The  channel option may be helpful when a channel is prone to generating an exceptionally large number of DSNs, or when it is desired to  handle DSNs generated by a particular channel in some special way, in combination with source specific rewrite rules.

The  channel option may be used on a channel to tell it to generate MDNs through the specified channel, rather than through the  (default)   channel. It takes a required argument, which is the name of the channel to which to enqueue the newly generated MDNs; normally, this should be some    channel that a site  defines for this purpose.

See also:
 * Process and reprocess channels
 * Notification message routing
 * Notification messages and postmaster messages channel options
 * Channel options