# man > flush(8)

---
type: CommandReference
command: flush
mode: man
section: 8
source: man-pages
---

## Quick Reference
- `flush` — Postfix fast flush server (daemon)
- `sendmail -qR destination` — request delivery of all mail queued for a destination
- `postqueue -f` — request delivery of all queued mail (same as sendmail -q)
- `flush` receives requests: `add`, `send_site`, `send_file`, `refresh`, `purge`

## Name
flush - Postfix fast flush server

## Synopsis
`flush` [generic Postfix daemon options]

## Options (Requests)
The `flush` server processes the following requests:

- `add sitename queueid` — Inform the server that a message with the given queue ID is queued for the specified destination.
- `send_site sitename` — Request delivery of all mail queued for the specified destination.
- `send_file queueid` — Request delivery of a specific deferred message.
- `refresh` — Refresh non-empty per-destination logfiles not read in `fast_flush_refresh_time` hours; delete empty logfiles not updated in `fast_flush_purge_time` days. Runs in background.
- `purge` — Perform a refresh for all per-destination logfiles.

## Configuration Parameters (key)
- `fast_flush_domains ($relay_domains)` — Destinations eligible for per-destination logfiles.
- `fast_flush_refresh_time (12h)` — Time after which a non-empty unread logfile is refreshed.
- `fast_flush_purge_time (7d)` — Time after which an empty logfile is deleted.
- `daemon_timeout (18000s)` — Time limit for a daemon process to handle a request.
- `ipc_timeout (3600s)` — Time limit for internal communication.
- `max_idle (100s)` — Idle time before terminating.
- `max_use (100)` — Max connections before terminating.

## See Also
- [smtpd(8)](https://www.chedong.com/phpMan.php/man/smtpd/8/markdown)
- [qmgr(8)](https://www.chedong.com/phpMan.php/man/qmgr/8/markdown)
- [postconf(5)](https://www.chedong.com/phpMan.php/man/postconf/5/markdown)
- [master(5)](https://www.chedong.com/phpMan.php/man/master/5/markdown)
- [master(8)](https://www.chedong.com/phpMan.php/man/master/8/markdown)
- [postlogd(8)](https://www.chedong.com/phpMan.php/man/postlogd/8/markdown)
- [syslogd(8)](https://www.chedong.com/phpMan.php/man/syslogd/8/markdown)