We take care of duplicates for you. We have multiple levels of checks and prevention, and it's not possible to send an email campaign to the same email address twice.

If an email address is already on your list (where you have previously given it to us, or the recipient has signed up), we filter it out.

Our email service provider (MailChimp) has duplicate detection as well.

Your clients will only get 1 copy of the email, no matter what.