DOKK / manpages / debian 11 / nullmailer / adminaddr.5.en
nullmailer-queue(8) System Manager's Manual nullmailer-queue(8)

nullmailer-queue - insert mail messages into the queue

nullmailer-queue

This program reads a formatted mail message from standard input and safely injects it into the outgoing mail queue.

The data sent into standard input is expected to have the following format: one line containing the envelope sender, one or more lines containing the recipients, a single blank line, and then the contents of the message exactly as it is to be transmitted to the destination. All lines are terminated with a single line-feed character. All addresses must contain a fully-qualified domain name.

Exits 0 if it successfully queues the message. If it failed to queue the message, it exits 1 and prints an error message to stdandard output.

If this file is not empty, all recipients to users at either "localhost" (the literal string) or the canonical host name (from /etc/mailname ) are remapped to this address. This is provided to allow local daemons to be able to send email to "somebody@localhost" and have it go somewhere sensible instead of being bounced by your relay host. To send to multiple addresses, put them all on one line separated by a comma.
If this file is not empty, its contents will override the envelope sender on all messages.

/var/spool/nullmailer/queue
The directory into which the completed messages are moved.
/var/spool/nullmailer/tmp
The directory in which messages are formed temporarily.
/var/spool/nullmailer/trigger
A pipe used to trigger nullmailer-send to immediately start sending the message from the queue.

nullmailer-inject(1), nullmailer-send(8)

This program should enforce system-wide configurable message length limits.