I also spent a long time looking for a reliable tool for checking email addresses and I can share my experience. Now I use a service that is ideal for me due to the balance between accuracy and speed of verification. For me, the key criteria were high accuracy in identifying invalid addresses and the ability to bulk upload - after all, my database is quite large, and it is simply unrealistic to check manually. Another important factor was the integration with my CRM, which greatly simplifies the automation of mailings and saves time. In terms of price, the service turned out to be quite adequate, especially considering the quality and functionality. During my work with this verifier, I noticed a significant improvement in the deliverability of letters and a decrease in the percentage of returns. In general, I recommend everyone to carefully evaluate not only the price, but also the set of functions that will really help in your business.

Of course, I will be happy to share my experience. I also tried many services for checking email addresses, and each had its pros and cons. But in the end, I settled on top email verifier https://snov.io/email-verifier — and here's why. The main criterion for me was the accuracy of verification, since I work with large B2B mailings, and every error affects the deliverability and reputation of the domain. Snov.io has a minimal level of false positives — this immediately caught my eye compared to other services. The second important factor was mass uploading and ease of processing large lists — everything is implemented at the highest level here. I was also pleasantly surprised by the integration with CRM, the ability to automate the sales funnel and immediately work with "live" contacts.