Can anyone explain what would be advantages/drawbacks if one uses local vs. server folder, like Draft etc.? Thanks!
Local folders remove mail from the server, so if you're limited on space on the server then you can store messages locally. Almost always this isn't an issue, and as mail in remote folders is still downloaded for offline use, you're not gaining anything for offline access there.
Choose a remote folder so you can access the mail from anywhere, unless you have a really specific reason otherwise.