Just in case anyone else needs it i found a solution...
Dim drafts As DistinguishedFolderIdType = New DistinguishedFolderIdType()
drafts.Id = DistinguishedFolderIdNameType.drafts
Dim usersbox As EmailAddressType = New EmailAddressType()
usersbox.EmailAddress = "emailaddress"
drafts.Mailbox = usersbox
createItemRequest.SavedItemFolderId.Item = drafts
Once the user running the application or service has access to create mail for that user this should work