Postfix command-line tools are listed below. Each one is fully documented in a manpage that comes with the Postfix distribution. This appendix is meant to give you an idea of what each command is used for. You should refer to the manpages for complete information about each of the commands:
Creates or queries alias databases.
Prints the contents of queue files, allowing administrators to display the text of a message in the queue.
Displays or changes Postfix parameters. Can display one parameter at a time, or the entire list of parameters.
Injects a message into the maildrop directory for delivery by Postfix.
Starts and stops the Postfix system. Can also be used for other Postfix maintenance, such as checking the configuration and flushing the queue.
Sends a request to a particular Postfix service. Meant to provide a way for shell scripts to communicate with Postfix services.
Locks a specified file for exclusive access. Provides a means for shell scripts to use Postfix-compatible locking.
Logs specified information to the system-logging facility. Provides a means for shell scripts to log information easily in a style similar to Postfix.
Creates or queries lookup maps. Much of the Postfix configuration information is kept in lookup tables that are created by the postmap command.
Provides user-level access to the Postfix queue. Changes to the queue requiring super-user privileges are managed by the postsuper command.
Provides super-user access to the Postfix queue. Allows an administrator to delete messages, place them on hold and release them from hold, and repair the queue structure, if necessary.
General Configuration and Administration
Email and DNS
Local Delivery and POP/IMAP
Hosting Multiple Domains
Blocking Unsolicited Bulk Email
Transport Layer Security
Appendix A. Configuration Parameters
Appendix B. Postfix Commands
Appendix C. Compiling and Installing Postfix
Appendix D. Frequently Asked Questions