-This may be set to C<spamc> to enable the use of SpamAssassin
-L<spamc(1)> for filtering spam before it is imported into git
-history. Other spam filtering backends may be supported in
-the future.
-
-This requires L<public-inbox-watch(1)>, but affects all configured
-public-inboxes in PI_CONFIG.
-
-Default: none