When i change in Settings from Preffered Folders to Recent Message, I discover this messages who appered just here and not in accounts.

So i discover that not one message is somehow "hidden", but four. I know that is a database wich store emails.
What do you think, if i delete this account, this operation delete also the releated messages from db ?
Maybe if i delete / reset accounts, this accounts get (probaly) a new internal ID and the relation between former db records and new account is broken and i do not see this messages again, but i wonder about wasted space if, after acc deletion, this emails wont deleted too.

LE: My to spammers