M v2.6.11 OR EARLIER: Handling of return value for $mhonarc::CB{Raw}MessageBodyRead Changed</a></small>
<li><small><a href="#v2.5.x-iso-2022-jp">UPGRADING FROM v2.5.x OR EARLIER: Default iso-2022-jp Converter Changed</a></small>
<li><small><a href="#v2.4.x-defrcname">UPGRADING FROM v2.4.x OR EARLIER: DEFRCNAME Change</a></small>
<li><small><a href="#v2.4.x-header-footer">UPGRADING FROM v2.4.x OR EARLIER: HEADER and FOOTER Removed</a></small>
<li><small><a href="#v2.4.x-mimefilters">UPGRADING FROM v2.4.x OR 