Comment 13 for bug 357864

Maybe mozilla should do what pine does. Don't allow custom From's unless it is
explicity turned on in the config. This will save clutter in the interface for
those who don't want it.

There should also be a build option to disable this for sysadmins that don't
want their users to do this (unless there is some way the sysadmin can set a
prefrence and not have the user override it. Is there?)