http4 component: Possible to post message attachments as "multipart/mixed" ?

Hi,

I need to upload a camel message body (text/xml) together with files (added
to camel message attachments) with dataHandlers, by posting it to a URL with
the camel-http/http4 component.
Works fine without attachments.

Is it possible to post attachments in a multipart message (base64 encoded,
boundary separated) in a very similar way as with the mail component ?

Could the "multipart message composition" be "borrowed" somehow from the
camel-mail component ?

What happens by default with the message attachments when I post a message
(body) with the http-component ?

Thanks in advance for any help...