:0 f
| ~/bin/encryptemail.pl | mail foobar@gmail.com

#   by [alan]
  #   See if addressed *directly* to me, and ..
  #   ..has not already been forwarded

  KEY             = "TheMagic"
  FORWARD_EMAIL   = "foo@example.com"

  :0
  *$   ^To:.*$LOGNAME(@|[^0-9a-z]|$)
  *$ ! ^$MYXLOOP
  {
      # now let's encrypt the body using mimencode

      :0 fbw
      |   echo "MIME-Version: 1.0" ;
          echo "Content-Type: application/crypt" ;
          echo "Content-transfer-encoding: base64" ;
          echo "" ;
          crypt $KEY | mimencode -b

      #   Now let's prepare the headers for forwarding the mail,
      #   and mark it so we don't loop

      :0 fhw
      | $FORMAIL   -I"Resent-To: $FORWARD_EMAIL" -I"$MYXLOOP"

      :0
      ! $FORWARD_EMAIL

  }

crypt $KEY | mimencode -b

~/bin/encryptemail.pl | mimencode -b

:0
| ~/bin/encryptemail.pl | sendmail -oi foobar@gmail.com

:0fb
| ~/bin/encryptemail.pl
:0
! foobar@gmail.com