I'm trying to import a list of email addresses from a competition I've run (with email opt in explicitly requested). I'd like to add these emails to my profiles, without overriding existing customers details.
I have the emails in a csv list.
When I import them and the update profiles (insert only - no updates), I get an error because a few thousand of the emails already exist (existing customers that entered the competition). This stops the uploading of the new emails (new customers who don't exist yet in Profiles but have entered the competition).
I tried to exclude the existing emails in Profiles but the exclusion fails.
How do I upload new emails from a csv file without overriding existing profile data?