Every day dozens of email accounts cease to exist, which causes emails to be returned each time you send an email. This is particularly tedious in large companies that have to send thousands of emails a day to their different customers, suppliers, etc.
The most practical solution is this tool called Validawy. It is responsible for thoroughly checking lists containing thousands of email addresses. Make checks by seeing the response time of each of them, confirming if it reaches its destination or if instead returns it for not already existing that account.
Once Validawy finishes his work, he shows you a list of all those accounts that no longer exist to delete them from the list, so that you can contact the person to whom he belongs to provide you with the correct new account.
You can free download Validawy and safe install the latest trial or new full version for Windows 10 (x32, 64 bit, 86) from the official site.
Devices: Desktop PC, Laptop (ASUS, HP, DELL, Acer, Lenovo, MSI), Ultrabook
OS: Professional, Enterprise, Education, Home Edition, versions: 1507, 1511, 1607, 1703, 1709, 1803, 1809