This is a call to everyone who has a sufficient experience in any email verifying software. Your knowledge is precious for everyone! Lately I have been experimenting with email grabbing (via SB) to compile niche lists, and then apply a lot of filtering to make them as relevant as possible. I then use Atomic Mail Verifier for the final verification. Then I upload the final list to my email delivery service (like MailChimp) and pray for good results and not getting banned. Please have in mind that I use my own static IP when verifying the emails, and that port 25 is open in this IP. So far I had a rather good performance and responses(Yay!) BUT I want to go bigger scale and verify a list of 100,000 emails with the Atomic Mail Verifier. Currently I worry that using the Software to check the smtp responses of the emails of such huge list will result in getting my static IP address banned from several servers. So my ultimate questions is this ***. is it reasonable to worry for getting blacklisted by the servers just for doing bulk smtp email validity requests? And if yes how to avoid that?! *** One common solution suggested is to use SOCKS5 proxies instead of my own IP when doing the test. However, as far as I know there are almost no SOCK5 proxy providers that offer the port 25 open that is required for the verification process. And even when someone offers them to you, those proxies get banned within minutes. Another bypass is just go for the syntax and domain verification checks, and leave the smtp response verification check behind. However, this is also not a perfect solution as it reduces the quality of the final email list, and may put you in danger when using it for marketing via your email delivery service/provider due to high bounces/errors reports. Of course one may argue that's better to get banned by an email marketing service than getting your static IP shitlisted. (the former can change much more easily than the latter). I will argue is that there has to be way to stay safe on both sides I will really appreciate your knowledge and feedback on the manner! And promise that once I find the right approach to make a guide on the topic for newbies like me!