When you import a participant list, our system will check to see if an email address in your import file already exists in the online participant list.
It will not, however, check to see if your import list has duplicates. It is up to you to make sure that your import list is clean and has unique email addresses and no duplicate rows.
There are some great Excel plugins you can use to check for and clean out duplicate records.
Personally, we love the tools at AbleBits.com .. you can grab an Excel plugin that will help with duplicate identification at: