I'm trying to get my webmail (tiscali) to act as a file-autoresponder. It offers a text-only autoresponder as a filter option so I was going to filter on a specific subject and trigger the autoresponder with a UUEncoded file as I can't change the header of the message sent by the autoresponder. However I've found that the autoresponder sends mail in MIME format, meaning the uuencoding is ignored. The relevant headers of a mail produced are below:

Content-Type: text/plain; charset=iso-8859-1
MIME-Version: 1.0
Now I can't add headers to the email sent by the auto-responder so I can't add the necessary content-type header for a MIME-encoded file. Is there any way round this or way of MIME-encoding that doesn't require a content-type header?