Where Hunter fits, and where it doesn't
Hunter is an email finder and verifier with a campaign tool on top. Give it a domain and it lists the addresses it has seen for that company, with the public sources it found them on. Give it a name and a domain and it returns the most likely address with a confidence score, often by working out the company's pattern (first@, first.last@). It's honest about where its data comes from, and for B2B prospecting it does the job well.
It fits when you already know who you want: a list of target companies, a named contact, a domain from your CRM. It fits less well when your market is thousands of small businesses you haven't identified yet. Hunter has a Discover feature for finding companies, but its index leans towards businesses with a footprint in B2B data. The family-run bakery is easy to find on a map and hard to find in a company database.
And Hunter's job ends at the address. What you write is up to you.
Published-site sourcing vs a database of addresses
The difference that matters for small businesses: ScoutKite never builds an address from a pattern. If anna@ isn't written on Harbour Physio's website, Scout doesn't send to it, even if every other address at the domain follows first@. Small business owners notice when someone has guessed their way in, and guessed addresses bounce more often, which is what slowly pushes a sender into spam folders.