You can use the SQL workbench under the Tools menu to find which household the email address in question belongs to. Type (or copy/paste) the following statement into the SQL Workbench and replace "email@gmail.com" with the actual email address you're looking for:
select h.filing_name as Household, c.display_as, c.contact_person from household h, communication c
where c.household_id = h.id and display_as = 'email@gmail.com'