Which of the following are Email Security Protocols?

Which symmetric algorithms have variable key length?

What is Mail Exchanger(MX) Record?

Which measure should be taken to tackle spam mails?

Which is different categories of viruses?

What is the function of the Reverse DNS Look up Technique in identifying spam mails?

What is a botnet?

What is the main difference between spyware and other malware?

Which of the following sites provide services for users to setup disposable emails?

What is an example of a captcha?

A client asks you to fix his computer because it has ransomware on it. He says he sees a message as soon as he loads windows, and cannot do anything else. What is the best way to fix this computer without losing any of his data?