Queuelifetime

From QMail-Toaster

queuelifetime

This file defines how long your server will attempt to process or deliver an email before bouncing it to the originating sender defined in the header of the email message.

The value in this file must be in seconds.

Once the maximum time has been met the message will bounce, with the new sender being defined in bouncefrom and coming from the domain defined in bouncehost.

The default for Qmail-Toaster is 86400 (one day).

man qmail-send excerpt:

Number of seconds a message can stay in the queue. Default: 604800 (one week). After this time expires, qmail-send will try the message once more, but it will treat any temporary delivery failures as permanent failures.