---
name: "lockspool"
section: "1"
platform: "linux"
package: "opensmtpd"
version: "7.9.0p0-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux", "openbsd"]
url: "https://new.carta.tech/lockspool"
---

# lockspool(1)

lock user's system mailbox

## NAME

**lockspool** – lock user's system mailbox

## SYNOPSIS

**lockspool** \[*username*\]

## DESCRIPTION

**lockspool** is useful for a client mail program to attain proper locking. **lockspool** obtains a *username.lock* for the calling user and retains it until stdin is closed or a signal like SIGINT, SIGTERM, or SIGHUP is received. Additionally, the superuser may specify the name of a user in order to lock a different mailbox.

If **lockspool** is able to create the lock file, “1” is written to stdout, otherwise “0” is written and an error message is written to stderr. **lockspool** will try up to 10 times to get the lock (sleeping for a short period in between tries).

Typical usage is for a user mail agent (such as [mail(1)](/mail/1.md)) to open a pipe to **lockspool** when it needs to lock the user's mail spool. Closing the pipe will cause **lockspool** to release the lock.

## FILES

- */var/mail/username.lock*

  user's mail lock file

## EXIT STATUS

The **lockspool** utility exits 0 on success, and 1 if an error occurs.

## SEE ALSO

[mail(1)](/mail/1.md), [mail.local(8)](/mail.local/8.md), [smtpd(8)](/smtpd/8.md)

## HISTORY

The **lockspool** program appeared in OpenBSD 2.4.