If you are talking about body->contents.text, that is not something that is set by rfc822_parse_msg(). In fact, that is not something that you should *ever* access in your application; it is strictly internal to c-client.
If you really insist upon using rfc822_parse_msg(), you use body->contents.offset which is the offset into the stringstruct that you passed as the argument to rfc822_parse_msg(), along with the body->size.octets.
body->contents.text is currently only used by the IMAP driver and by the sending modules (SMTP and NNTP send).
-- Mark --
http://staff.washington.edu/mrc Science does not emerge from voting, party politics, or public debate. Si vis pacem, para bellum.