Signing a Message
=================

   The function `mc-sign' will clearsign a message in the current
buffer.  `mc-write-mode' binds this function to `C-c / s' by default.

   When this function is called, Mailcrypt will prompt you for the
appropriate passphrase unless it is cached (see Passphrase Cache.).

   Mailcrypt will then pass the message to PGP for processing.
Mailcrypt will call the functions listed in `mc-pre-signature-hook' and
`mc-post-signature-hook' immediately before and after processing,
respectively.  The signed message will replace the original message in
the buffer.  *Do not* edit the message further with the signature
attached, because the signature would then be incorrect.  If you
discover you need to edit a message after you have signed it, remove the
signature first with the normal Emacs undo command `C-x u' (*note Emacs
Undo: (emacs)Undo.).

   The variable `mc-pgp-user-id' controls which secret key is used for
signing; it is described in See Encrypting a Message: Encrypting.  To
use a different secret key, pass a prefix argument to `mc-sign'.  (That
is, type `C-u C-c / s'.)  Mailcrypt will prompt for a string and will
sign with the first key on your secret keyring which matches that
string.