SOAP 1.1 with attachment (MIME)

Hello to all, I need to send a SOAP 1.1 message with attachments into format MIME to web service AXIS.

I tray with Microsoft.Web.Service2 but the attachments are in DIME format and not in MIME format !

Someone can tell me how i send SOAP + attachments (MIME) in Framework .NET 3.0/3.5 ?