i have unique emails on the left side of the join for emails that have previously bounced from a mailing list. i have contacts from our CRM on the right side of the join and in some cases we have duplicates of the same email (they are valid duplicates b/c they are tied to specific user records that span multiple entities in our platform so no chance of cleanup). I can’t seem to get the join to work when there are duplicate values.
I’d like to map/mark each instance of the records above as “undeliverable = true”… but when I try a join the duplicates are left out. i’ve tried inner and outer joins. any guidance on this is appreciated.