muttng && gpg

(maybe this is true for mutt(-devel) too, i'm not sure)

so. first you need a private key, there is a good howto about it here. then you need to copy gpg.rc (for example from /usr/share/doc/mutt-ng-20060402/samples/gpg.rc) to ~/.muttng, then add the following lines to your muttngrc

source ~/.muttng/gpg.rc
unset crypt_autosign
unset crypt_autoencrypt
set crypt_replysign
set crypt_replyencrypt
set crypt_verify_sig=yes
set pgp_sign_as="0xXXXXXXXX"

where XXXXXXXX is your keyid

for autmatic key downloading on checking signatures, add

keyserver-options auto-key-retrieve

to your ~/.gnupg/gpg.conf

that's all :)