Email Validation For B2B Sales Emails

For the innovative category of the 2023 ZeroBounce Hackathon.

There is no point in sending an email that a human will never read



Try the demo live here!



We have built a validation check that validates format and performs a SMTP validation step on the recipient MX. This works well, but it wouldn’t be a good hackathon without pushing the envelope — So we want to take it an extra step and innovate.

B2B sales, particularly in the tech space, frequently works with customers who have a web presence, so why not go another step and validate that the recipient domain has an active website? This further reduces the likelihood of sending email to a parked domain when reverifying old contact lists or as a sanity check on an existing one.


To build a scalable and accurate validator to maximize the chances of deliverability to a human.

The team recognizes the methodologies below are not new to the email industry. We decided to not only build a tool that validates emails but also add some additional information for email lookups, checking for an active website, and logo.


Reid WorkmanProject Lead / Developer - Former Email Lead at ESPLinkedIn


Validation Methodology

  1. Validate Email format - Start with the basics, is this a valid email address format?
  1. Transform Base email format - Transform syntax sugar to simple email.
    1. eg. to
  1. Validate Domain exists - Dig to validate the domain is valid
  1. Validate MX is valid - Does the domain accept email?
  1. SMTP Verification - Attempt to start a conversation about an email address.
    1. If we are blocked, apply a cooldown on the target IP and email address.

Code and APIs

All APIs used in this demo are internally built.


Future work

Hackathons rarely grow beyond their initial scope, however, if this project were to continue development, I’d add the following: