ipinfo.io - Simple IP address information.
CampaignKit - Email Validation for marketers. Detect invalid and malicious email addresses in your email lists.
ipdata.co - Get the Geolocation, Organisation, Currency, Timezone, Calling Code, Flag, Proxy, Tor and Threat intelligence data from any IPv4 or IPv6 address.
Null Bounce - Null Bounce is an email validation tool that helps companies decrease the bounce rate for email campaigns. Also, the service is available as an API, which can be used, for example, on sign-up forms to ensure that user submits a valid email address.
ifconfig.co - What is my IP address? — The best tool to find your own IP address, and information about it.
Captain Verify - Captain Verify is the best solution to Verify & Clean the validity of your emails.