Is Flex supports soap with attachments?

i am trying to consume SOAP webservice. In that one of service is required to have MIME attachment as a parameter to upload a file to the server.

I am passing as a ByteArray and File stream but i have no luck. in ecah service call it goes to fault and fault message as "Client error: SOAP Attachemnt missing."
Is Flex really supports MIME attachemtns for SOAP Webservices? if yes in which SDK it supports?