How to identify Draft from Inbox and Sent mails In ALL MAIl mailbox

I am working on a mail client Application for downloading开发者_StackOverflow gmail emails, which uses IMAP C-client library.

I want to download emails from "ALLMAIL" mailbox folder. as you know ALLMAIL folder consists of Inbox,Sent Mail and Draft Mails.

Here my requirement is to distinguish Draft from Inbox and Sent mails.

Usually if we download envelop of emails, that should give email's Draft info. But Gmail is failing to set this draft info.

So can you please suggest how to identify draft?

Thanks In advance Subbi

---

Gmail IMAP has some issue with setting the DRAFT flag, I faced the same issue when i was working with it. I deviced a workaround where I checked the delivered-to and return-path mail headers, if these headers where not there I assumed this to be a draft message.