...
Grant the person's Bugzilla account with all permissions, and with permission to grant all permissions to other users. This is done by following the "Users" link in Bugzilla, specifying the account by email address, clicking on the correct username, scrolling to "Group Access" and ticking the appropriate checkboxestwo checkboxes for the admin group, which will imply the other required permissions.
Added to private list
The private at spamassassin.apache.org mailing list is used for PMCish chat (see ProjectRoles); your Apache email addresses is added to this list, using your preferred email address to subscribe to private@ and your apache.org address to private-allow@ so it can be used to post to the list.
...