mh-max-inline-image-height

mh-max-inline-image-height is a variable defined in `mh-e.el'.
Its value is

nil

Documentation:
*Maximum inline image height if "Content-Disposition:" is not present.

Some older mail programs do not insert this needed plumbing to
tell MH-E whether to display the attachments inline or not. If
this is the case, MH-E will display these images inline if they
are smaller than the window. However, you might want to allow
larger images to be displayed inline. To do this, you can change
the options `mh-max-inline-image-width' and
`mh-max-inline-image-height' from their default value of zero to
a large number. The size of your screen is a good choice for
these numbers.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 7.0 of the MH-E package that is part of Emacs 22.1.