area: listverify
action: verifysingleemail
https://api.hypermail.com/api.php?apikey=YOURAPIKEYHERE&area=listverify&action=verifysingleemail&email=test@test.com&smtpverify=1&smtpreason=1
<response>
<email>Valid</email>
</response>
{
"email": "Valid"
}