Worn Pages gets reached out to frequently from customers asking them to update their contact information. In Mailchimp, which method is NOT used to update existing contacts?

Mailchimp does not offer a direct integration to import contact information from a personal email account (like Gmail or Outlook) for updating existing contacts. While you can import contacts from a CSV file, manually edit individual contact profiles, or use the API to overwrite contact data, there's no feature to scan your personal email for updated contact details and apply them to your Mailchimp audience. The other options are valid methods for updating existing contact information within Mailchimp.