Some long dormant bits in my brain are remembering something like this happening when the MIME type application/pgp-signature was introduced. Before then, people were using application/pgp for such things, and some were using other things like pgp-encrypt.

If the signature problem is a pgp signature problem, these docs may prove illuminating.

http://www.phildev.net/pgp/pgp_clear_vs_mime.html http://www.ietf.org/rfc/rfc2015.txt

Laura