john.doe@example.com,jane@smith-family.net,support@company.co.uk,info@subdomain.example.org Explanation: 1. john.doe@example.com - A valid email address with a username, domain, and top-level domain. 2. jane@smith-family.net - A valid email address with a username, domain, and top-level domain. 3. support@company.co.uk - A valid email address with a username, domain, and top-level domain. 4. info@subdomain.example.org - A valid email address with a username, subdomain, domain, and top-level domain. 5. Invalid email: not.an.email.com - Not a valid email address as it lacks a username before the '@' symbol. 6. Another invalid: @missing-username.com - Not a valid email address as it lacks a username before the '@' symbol. Note: The extracted email addresses are concatenated with commas without spaces.