rmail-search-mime-message-function

rmail-search-mime-message-function is a variable defined in `rmail.el'.
Its value is

nil

• This variable may be risky if used as a file-local variable.

Documentation:
Function to check if a regexp matches a MIME message.
This function is called by `rmail-search-message' if
`rmail-enable-mime' is non-nil. It is called (with point at the
start of the message) with two arguments MSG and REGEXP, where
MSG is the message number, REGEXP is the regular expression.