Dispositionchannel, notificationchannel Channel Options

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Notification and disposition channels (dispositionchannel, notificationchannel)

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 process channel. That is, the channel that needs to generate a DSN or MDN submits the DSN or MDN, respectively, to the process channel; and the process channel subsequently enqueues the DSN or MDN on to the appropriate outbound channel (back to the sender of the original message).

The notificationchannel channel option may be used on a channel to tell it to generate DSNs through the specified channel, rather than through the (default) process 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 process_something channel that a site defines for this purpose.

The dispositionchannel channel option may be used on a channel to tell it to generate MDNs through the specified channel, rather than through the (default) process 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 process_something channel that a site defines for this purpose.

The notificationchannel 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.