Fake or bot-generated contacts in your Mailchimp audience usually share a signup IP and have blank names. You can remove them as follows.
- In Mailchimp, filter your audience by status Pending.
- Identify contacts with blank names and a shared signup IP.
- Select those contacts and delete them permanently.
Why deletion is the only option. Pending contacts cannot be archived, so permanent deletion is the only way to remove them.
Check subscribed contacts too. Look for any subscribed contacts with the same signup IP and blank names, dated within the period the bot activity occurred, and delete those as well.