Perfect!  Can you update the list to include all of the candidate IDs in addition to these email addresses?
SELECT T2.candidate_id,T1.email_address FROM people AS T1 JOIN candidates AS T2 ON T1.person_id  =  T2.candidate_id
include all of the candidate IDs in addition to these email addresses refers to SELECT T2.candidate_id, T1.email_address; joining tables people and candidates on common identifier refers to JOIN ... ON T1.person_id = T2.candidate_id;