There is no way to prove someone is not viewing your email, you can only prove they are. One way to confirm if they are, even when you cannot see IP addresses connected to the mail server, is to trick them into alerting you.

Do spammers know if you open their email?

Can spammers tell if you open an email? Spammers can tell if you open an email when you or your email application interact with their message. When your webmail or mobile email app automatically downloads remote resources like photos or graphics, the spam sender immediately knows their content was viewed.

Why do hackers want your email address?

While a hacker cant login to any of your accounts unless they have your password, email address hacking gives them an easy way to target you with phishing attempts and malicious attachments that can help them figure out your password.

Why do I suddenly have thousands of emails?

Heavy Subscription Spam is a Warning Sign Your Personal Data Might Be Compromised. If you start receiving thousands of suspect emails (it could be as many as 60,000 in a 24-hour period) thieves may already have your identity and personal information, so dont just select and delete. Get ready to investigate.