MailReveal is a free online tool to validate and verify emails to avoid bounce. Test your Emails Deliverability. Check if Email Exist. build your quality list. mailreveal is an email testing tool that verifies MX, HOST, Deliverability, Catch-All, Username, and Overall Email Quality. make sure your email reaches the inbox.Email verification is a process of ensuring that an email is deliverable. In other words, Email verification makes sure that your email is in existence and able to receive messages. Email verification reduces the email bounce of your email campaign. Businesses all over the world use email verification to maximize the potential of their campaign to be successful.