Deliverbychannel Channel Option

Limiting time to deliver )
The  source channel option specifies the source channel used for the generation of nondelivery receipts associated with the DELIVERYBY SMTP extension in the absence of any other information. The default is to use the l channel if this option is not specified. Note that there should be few if any cases where this option should be set.

See also:
 * deliverbymin Option
 * SMTP and LMTP protocol channel options