When I choose "toggle flag" on an email for a gmail account on my Windows Phone (running Mango beta2) it adds a flag icon to the email on the phone and the email then shows up under the "flagged" pivot. The issue I'm having is that I don't know how to see flagged emails in the gmail web client. I had hoped that flagging an email would be equivalent to starring it on an Android phone but that doesn't seem to be the case. I did discover that I can either move or copy emails to the starred folder, but that's a few too many clicks ;) Thanks!
As far as I can tell the "flag" option is strictly on the device. It appears to be a half-a$s measure to address the lack of being able to star an email. Definitely a PITA. Anybody know if MS plans on fixing this?
You actually can star items by moving them to the starred folder. Not really a great solution but it does work, at least for the inbox. I'm pretty sure that this isn't MS's fault, and it's not something they can fix. Afaik you can't star emails on the iphone either. Of course you can on android, but that probably uses some proprietary protocol instead of imap.
Maybe someone with imap expertise can elaborate on this.