I'm in the process of moving an auto response email from our current in-house email system to Marketo. This auto response email is generated once a lead completes a specific form on our website.
My problem is, we've been collecting lead info into Marketo via this same form since we started using Marketo. So I have thousands of leads who already fit the criteria of having filled out this specific form.
How can I make sure that my campaign only affects leads going forward, and does not retroactively send to leads who have filled out this form in the past?