In .muttrc or somewhere else
# ask to sign all the
# outbound messages.
# when you answer a signed message, the response message will be
# signed too.
# when you answer an encrypted message, the response message
# will be encrypted too.
# Do you want to automatically verify incoming signed messages?
# Of course!
# delete pass phrase from the memory cache 0.5h
# after typing it.
# what key do you want to use to sign outgoing messages?
# Note: it is posible to set it to the user id, but
# this can be confuse if you have the same user id with different keys.
# EA3F0A87 is my key ID, you should change it to your own!
# Signing on the message body without using PGP/MIME with GnuPG
# As many programs can't use PGP/MIME (especially from M$), the <CTRL>P key
# will allow us to sign "as in the old times" (Application/PGP):
macro compose \CP "Fgpg --clearsign\ny"
# The next, <CTRL>S will allow us to sign using PGP/MIME with the private key
# that we have defined as default. This macro is not necesary, as we can
# do the same from the "P" menu:
macro compose \CS "Fgpg --clearsign\ny^T^Uapplication/pgp; format=text; x-action=sign\n"
# Publicizing Your Public Key
# again, change this to your own content.