[ patrick n. blackburn writes: ]
> Can I restrict 'who' access on a given list to be available only to
> addresses listed in my <listname>.restrict file?
> I know the config file permits 'who' to be set at open, closed, or
> list. None of these suits my needs.
Set 'who_access' to 'list' and set 'restrict_post' to your
<listname>.restrict file. However, that has the side effect of also
restricting posting and all other *_access parameters that are set to
'list' to that same restrict list.