mh-delay-invisible-header-generation-flag

mh-delay-invisible-header-generation-flag is a variable defined in `mh-e.el'.
Its value is

t

Documentation:
Non-nil means to delay the generation of invisible header fields.
Because the function `mh-invisible-headers' uses both
`mh-invisible-header-fields' and `mh-invisible-header-fields', it
cannot be run until both variables have been initialized.