Not minimized but generates a file 'emails.txt':

a = document.createElement('a');

a.download = 'emails.txt';

a.href = `data:text/plain,${Array.from(document.querySelectorAll('a')).map(a => a.href).filter(s => ~s.indexOf('mailto')).join(',')}`;

document.body.appendChild(a);

a.click();