---
name: "postlog"
section: "1"
platform: "linux"
package: "postfix"
version: "3.11.7-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux", "macos"]
url: "https://new.carta.tech/postlog"
---

# postlog(1)

Postfix-compatible logging utility

## NAME

postlog - Postfix-compatible logging utility

## SYNOPSIS

```

```

**postlog** \[**-iv**\] \[**-c** *config\_dir*\] \[**-p** *priority*\] \[**-t** *tag*\] \[*text...*\]

## DESCRIPTION

The [**postlog**(1)](/postlog/1.md) command implements a Postfix-compatible logging interface for use in, for example, shell scripts.

By default, [**postlog**(1)](/postlog/1.md) logs the *text* given on the command line as one record. If no *text* is specified on the command line, [**postlog**(1)](/postlog/1.md) reads from standard input and logs each input line as one record.

Logging is sent to [**syslogd**(8)](/syslogd/8.md) or [**postlogd**(8)](/postlogd/8.md), and to the standard error stream (with Postfix \< 3.8, [**postlog**(1)](/postlog/1.md) writes to the standard error stream only if that stream is connected to a terminal).

The following options are implemented:

- **-c** *config\_dir*

  The **main.cf** configuration file is in the named directory instead of the default configuration directory. See also the MAIL\_CONFIG environment setting below.

- **-i** (obsolete)

  Include the process ID in the logging tag. This flag is ignored as of Postfix 3.4, where the PID is always included.

- **-p** *priority* (default: **info**)

  Specifies the logging severity: **info**, **warn**, **error**, **fatal**, or **panic**. With Postfix 3.1 and later, the program will pause for 1 second after reporting a **fatal** or **panic** condition, just like other Postfix programs.

- **-t** *tag*

  Specifies the logging tag, that is, the identifying name that appears at the beginning of each logging record. A default tag is used when none is specified.

- **-v**

  Enable verbose logging for debugging purposes. Multiple **-v** options make the software increasingly verbose.

## SECURITY

```

```

The [**postlog**(1)](/postlog/1.md) command is designed to run with set-groupid privileges, so that it can connect to the [**postlogd**(8)](/postlogd/8.md) daemon process (Postfix 3.7 and later; earlier implementations of this command must not have set-groupid or set-userid permissions).

## ENVIRONMENT

```

```

- MAIL\_CONFIG

  Directory with the **main.cf** file. In order to avoid exploitation of set-group ID privileges, a non-default directory is allowed only if:

  - •

    The name is listed in the default **main.cf** file with the **alternate\_config\_directories** or **multi\_instance\_directories** configuration parameter.

  - •

    The command is invoked by the super-user.

## CONFIGURATION PARAMETERS

```

```

The following **main.cf** parameters are especially relevant to this program.

The text below provides only a parameter summary. See [**postconf**(5)](/postconf/5.md) for more details including examples.

- **config\_directory (see 'postconf -d' output)**

  The default location of the Postfix main.cf and master.cf configuration files.

- **import\_environment (see 'postconf -d' output)**

  The list of environment variables that a privileged Postfix process will import from a non-Postfix parent process, or name=value environment overrides.

- **syslog\_facility (mail)**

  The syslog facility of Postfix logging.

- **syslog\_name (see 'postconf -d' output)**

  A prefix that is prepended to the process name in syslog records, so that, for example, "smtpd" becomes "prefix/smtpd".

Available in Postfix 3.4 and later:

- **maillog\_file (empty)**

  The name of an optional logfile that is written by the Postfix [**postlogd**(8)](/postlogd/8.md) service.

- **postlog\_service\_name (postlog)**

  The name of the [**postlogd**(8)](/postlogd/8.md) service entry in master.cf.

Available in Postfix 3.9 and later:

- **maillog\_file\_permissions (0600)**

  The file access permissions that will be set when the file $maillog\_file is created for the first time, or when the file is created after an existing file is rotated.

## SEE ALSO

```
postconf(5), configuration parameters
postlogd(8), Postfix logging
syslogd(8), system logging
```

## LICENSE

```

```

The Secure Mailer license must be distributed with this software.

## HISTORY

The [**postlog**(1)](/postlog/1.md) command was introduced with Postfix version 3.4.

## AUTHOR(S)

```
Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA
Wietse Venema
Google, Inc.
111 8th Avenue
New York, NY 10011, USA
```