+.RE
+.RS 4
+.TP 4
+.B mbox
+
+All matching messages are output in the traditional, Unix mbox format
+with each message being prefixed by a line beginning with "From " and
+a blank line separating each message. Lines in the message content
+beginning with "From " (preceded by zero or more '>' characters) have
+an additional '>' character added. This reversible escaping
+is termed "mboxrd" format and described in detail here:
+http://homepage.ntlworld.com/jonathan.deboynepollard/FGA/mail-mbox-formats.html
+