Are you seeing this error in your Sync Details Report?
"looks fake or invalid, please enter a real email address., code: 400"
How do I fix this error? Time Error Message 23 Jan 2019 02:23:02 Error for the record: email@example.com, message: firstname.lastname@example.org looks fake or invalid, please enter a real email address., code: 400
Thanks and certainly.
The error is due to the email domain that does not pass the Mailchimp email domain standards that's why the email record is rejected. These email addresses will not be synced to Mailchimp.
If wanting these email addresses to be synced, you can validate them in Mailchimp.
If it continues please reach out to Mailchimp support here...