When you import an email list to your account in our platform, our system makes sure that there are no duplicate members on your newly imported list and it also checks to see if it contains any members who have previously unsubscribed and shouldn't be receiving that newsletter.
If you notice a reduction in your list members compared to what you expected, those are the two possible explanations. We are just taking care of your list, making sure it is updated and ready for action.
If you think this is not the case, we advise you to contact our support team, they will gladly help you out.