fn imap_of(condition: &Condition, gmail: bool) -> Option<ImapKey>Expand description
One condition as a server key: none when a server cannot say it (who the sender is to you, the day of the week): then the folder’s newest are asked, and checked here. A key may find more than the condition (what it finds is checked here, on its headers and parts), never less: what a server would leave out wrongly is not asked of it.