Hello,

Are emails downloaded twice if you have GMail's All Mail in your IMAP?
Will marking an email read also mark it read in All Mail?
How can I search globally using KMail's quick search bar?

Thanks.

Yeah, they are downloaded twice. There was an attempt at making something specialized for GMail for 4.14, but it was pulled at the last minute due to fairly critical bugs.

As far as I can tell, the quick search bar only works in the currently selected folder.