Sorting method on messages.
Type: -one of “date”, “date-received”, “from”, “mailbox-order”, “score”, “size”, “spam”, “subject”, “threads”, “to”, “reverse-date”, “reverse-date-received”, “reverse-from”, “reverse-mailbox-order”, “reverse-score”, “reverse-size”, “reverse-spam”, “reverse-subject”, “reverse-threads”, “reverse-to”
+one of “date”, “date-received”, “from”, “mailbox-order”, “score”, “size”, “spam”, “subject”, “threads”, “to”, “reverse-date”, “reverse-date-received”, “reverse-from”, “reverse-mailbox-order”, “reverse-score”, “reverse-size”, “reverse-spam”, “reverse-subject”, “reverse-threads”, “reverse-to”, “last-date”, “last-date-received”, “last-from”, “last-mailbox-order”, “last-score”, “last-size”, “last-spam”, “last-subject”, “last-threads”, “last-to”, “reverse-last-date”, “reverse-last-date-received”, “reverse-last-from”, “reverse-last-mailbox-order”, “reverse-last-score”, “reverse-last-size”, “reverse-last-spam”, “reverse-last-subject”, “reverse-last-threads”, “reverse-last-to”Default:
"threads"