double byte chars in From header

[Viktor Pavlenko <vp@example.com>]

I'm having trouble viewing email with double byte characters in the
`From' header. VM under emacs chokes and I have to edit my mail box
manually to get rid of the offending characters that look, for
instance, like this:

=?ISO-2022-JP?B?GyRCJUAlUyVDJUklKCVJJSIlayVJGyhC?=

Is it a VM problem? What does the standard say?

Thanks,
Viktor