Hunter.io is an online tool that helps businesses find email addresses associated with a specific domain name.

It's useful for sales, marketing, and recruiting professionals who need to contact potential customers or job candidates via email.

Hunter.io offers a range of features, including domain search, email finder, email verification, and email tracker.

With Hunter.io, users can quickly find and verify email addresses, and track whether emails have been opened or not. This can help businesses save time and increase their chances of connecting with the right people. Overall, Hunter.io is a valuable tool for anyone looking to streamline their email outreach efforts and improve their email marketing campaigns.