gpgmailtunl - Encrypts an email message into the body of another email.

       Francis J. Lacoste <francis.lacoste@iNsu.COM>

       Copyright (c) 1999, 2000 iNsu Innovations Inc.

       This program is free software; you can redistribute it and/or modify  it  under  the  terms  of  the  GNU
       General  Public License as published by the Free Software Foundation; either version 2 of the License, or
       (at your option) any later version.

       To  extract  an email to be forwarded to the final user you pipe the encrypted email to gpgmailtunl using
       the decrypt switch.

       Once decrypted, the encapsulated email message will be sent to the original destinator of the message.

   OPTIONS
       homedir
           Sets an alternate gpg home directory. (This is where the keyrings are stored.)

       secret-file
           File from which the secret to unlock the private used to decrypt the message can be read.

gpgmailtunl is a filter program that either encrypts an email message using the Gnu Privacy Guard and
       sends it to another recipient or decrypt an email message and forwards unencrypted to another
       destination.

       It can be used to exchange emails across an open network between two trusted systems.

       To encapsulates an email within another you pipe the message to gpgmailtunl.

   OPTIONS
       GetOptions( \%opt, "encrypt", "decrypt", "sign", "secret-file=s",          "from=s", "to=s", "subject=s",
       "homedir=s", "local-user=s",          "recipient=s",        )
         or usage;

       to  This is the address to which the encrypted message will be sent. This is the only required fields.

       recipient
           This  sets  the  keyid that will be used to encrypt the outgoing message.  If unset, gpgmailtunl will
           try to find a key matching the to option.

       subject
           Sets the subject of the outgoing message. This defaults to "Encrypted mail".

       from
           Sets the From header line of the outgoing message which will contains  the  encrypted  one.  sendmail
           will provides a default one if this is not set.

       sign
           If  this option is used, the outgoing message will be signed. In this case you should probably use to
           local-user and secret-file options.

       secret-file
           File from which the secret to unlock the private used to sign the message can be read.

       local-user
           The keyid of the user that should sign the outgoing message. The default user will  be  used  if  not
           specified.

       homedir
           Sets an alternate gpg home directory. (This is where the keyrings are stored.)

       gpgmailtunl - Encrypts an email message into the body of another email.

gpg(1) gpgmailtunl(1) GnuPG(3)

perl v5.36.0                                       2022-10-13                                    GPGMAILTUNL(1p)

       gpgmailtunl [options] --encrypt | --decrypt

       This program is intended to run from program like procmail or sendmail to create an email tunnel between
       two systems.  Of course this is not as secure as using gpg as an end user program, it may be convenient
       in certain case.