I've imported a static list of leads without email but with lots of other data.
Now I want to re-upload just the email addresses. How can I make sure that the email addresses are matched with the correct IDs without creating duplicates?
Let's not get ahead of ourselves... why not delete these leads if they can be identified (in the UI) and reimported?
In these cases, we cannot match on Email for a standard list upload. If you did have API access, you are right that you could insert the correct email tied to the Marketo ID.
My preferred method is to
If these are new leads in an identified static list I'm saying just trash them all, like you are!
Thank you very much for your help, I have deleted the leads and re-imported them with the email, that seemed to be easiest