---
name: "gpg-mail-tube"
section: "1"
platform: "linux"
package: "gnupg"
version: "2.4.9-4"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/gpg-mail-tube"
---

# gpg-mail-tube(1)

Encrypt rfc822 formatted mail in a pipeline

## NAME

**gpg-mail-tube** - Encrypt rfc822 formatted mail in a pipeline

## SYNOPSIS

**gpg-mail-tube** \[*options*\] *recipients*

## DESCRIPTION

**gpg-mail-tube** takes RFC-822 formatted mail on stdin and turns it into a PGP/MIME encrypted mail which is then written to stdout.

The recipients must be plain mail addresses (e.g. **foo@example.org**) and should in general list the To and Cc addresses contained in the mail.

## OPTIONS

**gpg-mail-tube** understands these options:

- **--verbose** **-v**

  Enable extra informational output.

- **--quiet** **-q**

  Try to be as quiet as possible.

- **--log-file *file***

  Write log output to *file*.  Use ‘*socket://*’ to log to a socket.

- **--no-stderr**

  Suppresses all output to stderr.  This is useful for callers which don't distinguish stdout and stderr.  To get diagnostics the option **--log-file** can be used.

- **--header *name*=*value***

  Add the mail header "*name*: *value*" to the output.

- **--setenv *name*=*value***

  Put the given environment string into the environment of this process and of the called gpg.  This option is required if there is no other way to set the environemt.

- **--as-attach** **-a**

  Do not write a PGP/MIME mail but emit a simple body along with an attachment containing the encrypted body of the input mail.  If the input was a plain text message a simple encrypted file will be attached.  If the input was a multipart MIME message the encrypted file is of type message/rfc822.

- **--gpg *gpgcmd***

  Use the specified command *gpgcmd* instead of **gpg**.

- **--vsd**

  Use the gpg from a *GnuPG VS-Desktop®* AppImage.  The AppImage is started if it is not running.  A symlink named ‘*~/.gnupg-vsd/gnupg-vs-desktop.AppImage*’ needs to link to the actually to be used AppImage.

- **--version**

  Print version of the program and exit.

- **--help**

  Display a brief help page and exit.

## EXAMPLES

The following options can be used in a local transport rule of the Exim MTA which assumes that that **check\_local\_user** has been used in the router.

```
transport_filter = /usr/local/bin/gpg-mail-tube --setenv HOME=${home} \
                   --no-stderr -- $pipe_addresses
```

For a remote transport the use of **size\_addition** and an explicit setting of the user and its home directory might be required.

## DIAGNOSTICS

The program returns 0 on a successful encryption or a non-zero value on error.  Note that on error some output might have already been written to stdout.

## SEE ALSO

[**gpg**(1)](/gpg/1.md),

The full documentation for this tool is maintained as a Texinfo manual. If GnuPG and the info program are properly installed at your site, the command

```
info gnupg
```

should give you access to the complete manual including a menu structure and an index.