mh-scan-body-regexp

mh-scan-body-regexp is a variable defined in `mh-scan.el'.
Its value is

"\\(<<\\([^
]+\\)?\\)"

Documentation:
This regular expression matches the message body fragment.

Note that the default setting of `mh-folder-font-lock-keywords'
expects this expression to contain at least one parenthesized
expression which matches the body text as in the default of
"\\(<<\\([^\n]+\\)?\\)". If this regular expression is
not correct, the body fragment will not be highlighted with the
face `mh-folder-body'.