Alex

Unused CSS finder crawls your website (following all the internal links), analyses all the pages and provides a list of unused css-selectors found in your stylesheets.

This free SSL Checker recursivley crawls your website (following all internal links) and finds pages that generate mixed content warnings in browsers.

Jitbit's Email List Cleaner lets you clean UNLIMITED email lists. The cleaner removes duplicates, malformed emails, disposable mailboxes (like Mailinator or Maildrop), non-existing domains and domains with invalid MX records (i.e. no email server present) etc.