mysql query taking 46 seconds - needs to be more efficient

Question

I have arrived at a query that gives me what I want but it is not efficient and takes over 45 seconds to execute. How can I modify to make this quicker?

SELECT * 
FROM   (SELECT DISTINCT email, 
                    title, 
                    first_name, 
                    last_name, 
                    'chauntry' AS source, 
                    post_code  AS postcode 
    FROM   chauntry 
    WHERE  mailing_indicator = 1) AS x 
   LEFT JOIN (SELECT email, 
                     Avg(amount_paid)                AS avg_paid, 
                     Count(*)                        AS no_times_booked, 
                     Count(DISTINCT( Month(added) )) AS unique_months 
              FROM   chauntry 
              WHERE  added >= Now() - INTERVAL 1 year 
              GROUP  BY email) AS y 
          ON x.email = y.email

here are the data fields

here are the column headings I am after

Answer 1

DRapp, appreciate the detailed feedback - spot on about the date being an oversight.

Are we talking about something like the below to speed up my query? I cant find much info about creating a covering index and the source of the below one was questionable.

ALTER TABLE `chauntry` 
  ADD INDEX(`mailing_indicator`, `email`); 

ALTER TABLE `chauntry` 
  ADD INDEX covering_index (`added`, `email`, `amount_paid`);