How to replicate Zerobounce Gmail auth.

[notmyrealnameoryear88]

I understand how Zerobounce works for the most part when it comes to catch-all (some cases im not sure, but i assume part might be heuristics around response time) but for gmail specifically it says mailbox_not_found which they claim is 100% accurate. if its 100% accurate it must not be a heuristic or ml model they must be getting a non 250 ping from gmail. No matter what i try with smtp handshake, gmail always returns 250 even for the same emails that zerobounce confidently says does not exist. AFAIK zerobounce has no insider connections to google/yahoo/msft etc everything they do theoretically could be done by anyone. I'm not trying to compete with them im just trying to figure out the logic behind this specific instance that they can be so confident it doesnt exist.

 

[notmyrealnameoryear88]

I understand how Zerobounce works for the most part when it comes to catch-all (some cases im not sure, but i assume part might be heuristics around response time) but for gmail specifically it says mailbox_not_found which they claim is 100% accurate. if its 100% accurate it must not be a heuristic or ml model they must be getting a non 250 ping from gmail. No matter what i try with smtp handshake, gmail always returns 250 even for the same emails that zerobounce confidently says does not exist. AFAIK zerobounce has no insider connections to google/yahoo/msft etc everything they do theoretically could be done by anyone. I'm not trying to compete with them im just trying to figure out the logic behind this specific instance that they can be so confident it doesnt exist.

Also should note i tested with an email, no inbox found, created it and 3 minutes later inbox found. so it HAS to be pinging in some way to know it was created and didnt exist prior. This only works on gmail for them specifically if you use a google domain they run into the catch all where it gets a few rare ones wrong

 

[alphasim7]

i'm also interested in this, i use zerobounce for many years and always liked their business model

 

[tropical paradise]

not sure what you're talking about, gmail is not catchall like yahoo