Function after_fetch 

pub(crate) fn after_fetch(
    account: &Account,
    new: &[PathBuf],
    first: bool,
) -> usize

Mail just fetched into an account’s inbox (new; nothing on its first fetch, which brings two weeks of it, nor what was there before), judged as the Porch judges it, protections first: what your own filter judges, of a class you chose “Move to spam” for, goes into the account’s Junk folder on the server, as the Junk button does but without a keyword nor a label; of a class you chose “Flag only” for, it stays where it is. Each move and each flag goes into this device’s logs of what the filter did: the Porch lists them among its catches (“Not spam” brings one back), and the training learns from them until you say otherwise. It reaches the server: never on the window’s thread, nor inside a watcher’s own. How many moved.