method
select
select(mailbox)
public
Sends a SELECT command to select a mailbox so that messages in the mailbox can be accessed.
After you have selected a mailbox, you may retrieve the number of items in that mailbox from @responses["EXISTS"][-1], and the number of recent messages from @responses["RECENT"][-1]. Note that these values can change if new messages arrive during a session; see #add_response_handler() for a way of detecting this event.
A Net::IMAP::NoResponseError is raised if the mailbox does not exist or is for some reason non-selectable.