We are trying to download customers who have opened or clicked an email campaign so that this can be compared to our main database.
This seems simple enough to do for a one off BAU send within the delivery.
However, for an always-on campaign is it right that i would need to go in to every single send to see this?
Yes, if you have a recurring campaign with multiple execution deliveries, then indeed you need to extract that 1 by 1.
Other option is to do a technical workflow for extraction which can combine all data together, extract to a file and send to e.g. a SFTP server.