Problem scenario
You are not sure if an email address is associated with spam. Someone make comments on your blog. You are not sure if they are legitimate comments or if it is someone trying to spam a website or create a message that is an advertisement. What should you do to check-in on the email address?
Solution
Try https://cleantalk.org/blacklists/
On cleantalk.org you can search for IP addresses, email addresses, or domains (FQDNs of a URL).