Notices, nonurgentnotices, normalnotices, urgentnotices Channel Options

Undeliverable message notification times
The,  ,  , and   channel options control the amount of time an undeliverable message is silently retained in a given channel queue. The MTA is capable of returning a series of warning messages  to the originator and, if the message remains undeliverable, the MTA will eventually return the entire message.

Different return handling for messages of different priorities may be explicitly set using the ,  , or   channel options. Setting values for the  option is equivalent to setting those values for ,  , and  , so those values will be used for all messages. (In particular, if you wish to have, for example, an  setting override a more general   setting, then the   option must appear after the   option.)

This channel option&#x27;s required argument is a list of up to five monotonically increasing positive integer values. These values refer to the message ages at which warning messages are sent. The ages have units of days if the MTA option  is 0 or not specified in the MTA option file, or hours if the MTA option   is 1. When an undeliverable message attains or exceeds the last listed age, it is returned (i.e., bounced). When it attains any of the other ages, a warning notice is sent. (Note that when  is 0, so that the ages are interpreted as days, the ages to be exceeded are interpreted as full, twenty-four hour days; for instance, in order for a   value of   to apply to a message, the message must have been tried already for a full twenty-four hours. For instance, if the  , as is usual, is configured to run at thirty minutes after midnight each day, and if the initial   value is  , then a message originally submitted on the first of a month will not get a notification message generated until thirty minutes after midnight on the third of the month; consider that on the second of the month, the message had not yet been being tried for a full twenty-four hours.)

The default if no  channel option is given is to use the   setting for the local, l, channel. If no setting has been made for the local channel, then the defaults 3, 6, 9, 12 are used meaning that warning messages are sent when the message attains the ages 3, 6, and 9 days (or hours) and the message is returned after remaining in the channel queue for more than 12 days (or hours).

If you wish to change the notification ages for all of your channels, then the simplest thing to do is to add a  channel block at the top of your configuration (assuming you don&#x27;t already have one) and set the appropriate   options there.

See also:
 * Notification message generation timing
 * return_units MTA Option
 * Scheduler task options
 * mtpriority_policy MTA Option
 * Notification messages and postmaster messages channel options
 * Channel options