Losing a right-joined row when doing a NOT IN

I have three tables:

email_addr_bean_rel

    bean_id  |  email_address_id

email_addresses

    id       |  email_address

prospect_lists_prospects

    id       |  related_id

The above is a huge simplification to demonstrate the issue. What I need is a list of all related_ids and all available email addresses. But I have to start the query on the email_addresses table. So I'm using a RIGHT JOIN to get any related_ids that don't have e开发者_Go百科mail addresses. Here is the query:

SELECT 
       plp.related_id,
       ea.email_address
FROM   email_addresses AS ea 
       JOIN email_addr_bean_rel AS eabr 
         ON ea.id = eabr.email_address_id 
       RIGHT JOIN prospect_lists_prospects AS plp 
         ON eabr.bean_id = plp.related_id 
WHERE
      ea.email_address NOT IN ("x", "y", "z")

If I take out the WHERE clause, I get all related ids and the email_address is set to NULL for the ones that don't match up (as expected). But when I add in the WHERE clause, I lose those RIGHT JOINED records.

Is there some aspect of NOT IN or RIGHT JOIN that I'm missing that would cause this?

ea.email_address is NULL. But NULL NOT IN ("x", "y", "z") always evaluates to NULL.

I think you need this:

WHERE (ea.email_address is NULL) or (ea.email_address NOT IN ("x", "y", "z"))