I've patched abook a bit to make the usage of mutt's PGP features
more comfortable. Perhaps this may be of some use for others as
well. You can get it from 

       http://www.icir.org/robin/abook

The patch introduces three new address book properties for a person:

 - A flag indicating whether mails send to this recipient are to be
   encrypted and/or signed by default.

 - If encryption is activated, which key is be used for it

 - What the recipient does like more: PGP/MIME or old style
   application/pgp

(Note that after applying the patch, you'll have to increase the
values of abook's extra_column and extra_alternative options by 3 to
see the same fields as before.)

To make use of the new properties, two additional Python scripts are
enclosed with the patch (you'll need Python >= 2.0 for them)

(1) "abook2mutt.py" is an extended export filter. It outputs
    send-hooks that activate encryption/signatures for recipients.

    Additionally, it can output aliases (works as abook's export
    filter) and "color index" patterns which highlight all mails
    send from users in your address book (effect comparable to
    abook's contrib/whitelist, but takes another approach)

    Run abook2mutt.py without arguments to see an short explanation 
    of its options.

    Example:

    ----- cut ------------------------------------------------------------
               1 - Name            : Joe User
               2 - PGP             : Encrypt and sign
               3 - Key ID          : 0x12345678
               4 - PGP/Mime        : Yes
               E-mail addresses:
               5 -             joe@no.where
               6 -
    ----- cut ------------------------------------------------------------

    > ./abook2mutt.py -c cyan -a -p <~/.abook.addressbook
    send-hook . set pgp_autoencrypt=no
    send-hook . set pgp_autosign=no
    send-hook . set pgp_create_traditional=no
    alias joe Joe User <joe@no.where>
    color index cyan default '~f "joe@no\.where" | ~e "joe@no\.where"'
    send-hook "joe@no\.where" set pgp_autoencrypt=yes
    send-hook "joe@no\.where" set pgp_autosign=yes
    send-hook "joe@no\.where" set pgp_create_traditional=no
    pgp-hook "joe@no\.where" 0x12345678
    
    (The default hooks may be suppressed with option -d)

(2) "mail2abook.py" is a substitute for mutt's create-alias function
    (and for abook's contrib/mail2alias.py). In addition to
    extracting name and email address from the mail given on stdin,
    it tries to detect whether PGP is used and inserts corresponding
    items into abook's address book.


Finally, "abook_wrapper" is a simple wrapper script which simplifies 
the integration into mutt. If you edit the first few lines of it to
contain the correct paths, you can insert something like this into
your ".muttrc":

macro index a   "|abook_wrapper --mail\n:source ~/.mutt/abook\n"
macro pager a   "|abook_wrapper --mail\n:source ~/.mutt/abook\n"
macro index A   "!abook_wrapper\n:source ~/.mutt/abook\n"
macro pager A   "!abook_wrapper\n:source ~/.mutt/abook\n"

Typing 'a' will then create an addressbook entry for the current mail and 'A'
will start abook itself. In both cases, mutt's configuration is
updated with the new aliases/pgp-hooks/patterns afterwards.

Any comments and suggestions are welcome!

Robin Sommer <robin@icir.org>


THANKS
======

- Jean-Sebastien Morisset for his suggestions and "abook_wrapper"

- Mathias Gumz for updating the patch to abook 0.5.{1,3}

- B. L. Jilek for updating the patch to abook 0.5.5