Question
Opinions on Kickbox, BriteVerify or TowerData? We have about 300K subscribers in our database. With each new batch of new subscribers, we see 5-10% of them using invalid emails. This level seems too high for comfort so we are looking to automate email verification / authentication for all new subscribers as they come in.
Answer
There's quite a few in the market. Some are really expensive and most of them use the same techniques. I'd highly recommend to try MoonMail's tool which is pretty simple, straightforward, though you can only upload lists of recipients of up to 250 emails.
https://moonmail.io/email-verification-email-list-cleaning/