使用ews下载带附件的邮件

I have a requirement in which I need to download email and save it( as eml file) and each its attachment as separate files using java and ews managed api. After some search on internet I have written following java code, it seem to be doing what I want. However I have some doubts about its efficiency since I think in this approach each attachment is downloaded twice from remote. Is that comment correct and if its, is there a way to do this more efficiently?I have a requirement in which I need to downloa