How to upload subscriber base in Mailchimp?

Question

Domain Name System

Good afternoon. When uploading a list with users (on a mailing list), Mailchimp says there is a "critical" issue
"Our automated abuse-prevention system, Omnivore, has flagged your recent import for issues that could affect the delivery of your campaigns. Your list is likely to Internet service providers set strict limits on undeliverable
mail and abuse complaints, which we have to abide by as an email service provider. warning.
To send to your list again, you'll need to undo your most recent list import to remove the new addresses. After you've removed the problematic addresses, you'll be able to send to your list."
Well, it worries him. What does "
To send to your list again, you'll need to undo your most recent list import to remove the new addresses."
What are these new addresses and why?

Answer 1

I propose to shoot for such names of questions.
but on the problem, if you are importing the database, you need, as it were, confirmation of users so as not to get into spam

Answer 2

Mailchimp considers the last addition to your database to be too "dirty", which can be indicated by the presence of stop addresses, service addresses, broken addresses, trap addresses, etc. or it simply matches some known database used by spammers. Of course, you can try to clean them up, for example, validate the addresses and throw out the role ones. But most likely, the problem is not in Mailchimp, but in your database and the way you get it. Make mailings only to those users who unambiguously subscribed themselves, use double opt-in. If there was no double opt-in, exclude from the current database all users who have at least some suspicion that they are not real users, for example, leave only those for which there are transactions.