mh-fetch-x-image-url

mh-fetch-x-image-url is a variable defined in `mh-e.el'.
Its value is

nil

Documentation:
*Control fetching of "X-Image-URL:" header field image.

Ths option controls the fetching of the "X-Image-URL:" header
field image with the following values:

Ask Before Fetching
You are prompted before the image is fetched. MH-E will
remember your reply and will either use the already fetched
image the next time the same URL is encountered or silently
skip it if you didn't fetch it the first time. This is a
good setting.

Never Fetch
Images are never fetched and only displayed if they are
already present in the cache. This is the default.

There isn't a value of "Always Fetch" for privacy and DOS (denial of
service) reasons. For example, fetching a URL can tip off a spammer
that you've read his email (which is why you shouldn't blindly answer
yes if you've set this option to "Ask Before Fetching"). Someone may
also flood your network and fill your disk drive by sending a torrent
of messages, each specifying a unique URL to a very large file.

The cache of images is found in the directory ".mhe-x-image-cache"
within your MH directory. You can add your own face to the "From:"
field too. See Info node `(mh-e)Picture'.

This setting only has effect if the option `mh-show-use-xface-flag' is
turned on.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 7.3 of the MH-E package that is part of Emacs 22.1.