Mailtester.com vs. AtData

Check if an e-mail address is valid or not. Our email list checker will lookup and check emails to see if they are valid. We have Mailchimp omnivore checker and other integrations like MailChimp, Activecampaign

AtData's flagship email verification service, SafeToSend, leads the industry in accuracy, security, speed, and ease of use to provide comprehensive email data hygiene and protection against costly, problematic addresses. SafeToSend will confirm the email address is valid by determining if not only the syntax is correct but also if the address meets ISP-specific requirements. We will fix typos, formatting, syntax and other input errors while weeding out damaging addresses to alleviate risk and save your sender reputation.