I use on desktop Thunderbird with enigmail, but I couldn't reach it on Z yet. (Capn_Fish!)

I've compiled pine earlier, but I missed the feature of enigmail, that the encrypted messages are stored encrypted with my own key, too. So they can not be read in plain text but I can read with my secret key.

Two days ago I tried it again and here is the solution:

1. Some new scripts are created:
# cat .gnupg/encrypt
TOLIST=`echo $* |awk '{for(i=1;i<=NF;i++) {printf(" -r %s", $i)}}'`
/usr/bin/gpg -ea $TOLIST

# cat .gnupg/encryptsigned
TOLIST=`echo $* |awk '{for(i=1;i<=NF;i++) {printf(" -r %s", $i)}}'`
/usr/bin/gpg -sea $TOLIST

# cat .gnupg/sign  
/usr/bin/gpg --clearsign

2. Insert them as filters to .pinerc:
# This variable takes a list of programs that message text is piped into  
# after MIME decoding, prior to display.
display-filters=_BEGINNING("-----BEGIN PGP MESSAGE-----")_ /usr/bin/gpg -t,
       _BEGINNING("-----BEGIN PGP SIGNED MESSAGE-----")_ /usr/bin/gpg -t

# This defines a program that message text is piped into before MIME
# encoding, prior to sending
sending-filters=~/.gnupg/encrypt _RECIPIENTS_ my.name@my.domain,
       ~/.gnupg/encryptsigned _RECIPIENTS_ my.name@my.domain,

Pine will ask you for filter before sending. The two encypting filter encrypt the message for each recipient (To: and Cc:) and for myself (my.name@my.domain,}, too.

One feature is missing: It doesn't encrypt the attachment!