On 2003-01-19, Josh Huber <huber@alum.wpi.edu> wrote:
> We could have some other tag, such as "pgpauto", which selected plain
> PGP when there were no other attachments, but used pgp/mime if there
> were.

Did just that (and this message is a test of the function as well
(-:). Use `M-x mml-secure-message-sign-pgpauto' to sign messages; gnus
should figure the rest out by itseld.

Here is the patch: