We are looking to purge our system of any leads who have never ever opened an email from us and who aren't registered users on our site. (For our registered users, we are automatically put into a SFDC campaign called "User Registration"). I've built a smart list using the filters "Not In Member of SFDC campaign = User Registration" , "Was Sent Email = Any / On or Before = Today" and "Not Opened Email = Any / On or Before = Today" and have come up with almost 30k leads. I double checked some lead records and the majority all look good. However, I double checked one particular email on the smartlist and found they are associated with 2 records in SFDC. The 1st record had zero activity while the 2nd record had opened/clicked emails and is apart of the SFDC campaign = User Registration. Can I assume that if I delete the leads in this smartlist, Marketo will only delete the 1st record with no activity and keep the 2nd record who is a registered user? Has anyone else tried anything like this? We would obviously export the Inactive smartlist and save it just to have on file.