C: A001 SELECT INBOX
  S: * FLAGS (\Deleted \Seen \Flagged)
  S: * OK [PERMANENTFLAGS (\Deleted \Seen \Flagged)] Limited
  S: * 3 EXISTS
  S: * OK [UIDVALIDITY 1]
  S: * OK [UIDNEXT 1]
  S: * LIST () "/" INBOX
  S: A001 OK [READ-WRITE] SELECT completed
  C: A002 IDLE
  S: + idling
  ...time passes; new mail arrives...
  S: * 4 EXISTS
  C: DONE
  S: A002 OK IDLE terminated
  ...another client expunges message 2 now...
  C: A003 FETCH 4 ALL
  S: * 4 FETCH (...)
  S: A003 OK FETCH completed
  C: A004 IDLE
  S: * 2 EXPUNGE
  S: * 3 EXISTS
  S: + idling
  ...time passes; another client expunges message 3...
  S: * 3 EXPUNGE
  S: * 2 EXISTS
  ...time passes; new mail arrives...
  S: * 3 EXISTS
  C: DONE
  S: A004 OK IDLE terminated
  C: A005 FETCH 3 ALL
  S: * 3 FETCH (...)
  S: A005 OK FETCH completed
  C: A006 IDLE