What scope do I use to grant imap access to gmail with oauth?

I've not worked 开发者_StackOverflow中文版with oAuth before but now I'm building a web app which need to fetch all mail from a specific label in gmail and using IMAP with oAuth seems like the right way to go. I've only just started but I've registered my development domain with google so that I've got a consumer key and secret however on the "Test your AuthSub registration here." link at the google page I only grant access to the calendar (which I don't even need) I've searched some but all this new stuff is very confusing and I can't find what scope parameter to use, I've tried changing the scope parameter to https://mail.google.com, ..go../mail/, ..go../mail/user@gmail.com/imap/ and ..go../mail/imap/ where ..go.. is https://mail.google.com and https://google.com

So could anyone point me in the right direction?

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The scope when you use 3 legged is

https://mail.google.com/