Which technology is commonly used to verify the authenticity of email senders?

The chosen answer, DKIM (DomainKeys Identified Mail), is the standard technology used to verify the authenticity of email senders. DKIM works by allowing an organization to take responsibility for a message that is in transit. It uses cryptographic techniques to sign an email with a private key, which corresponds to a public key published in the organization’s DNS records. When the email is received, the recipient's server can check this signature against the public key to confirm that the message was indeed sent by the legitimate sender and that it hasn't been altered during transmission.

This process helps to combat email spoofing, ensuring that users can trust the emails they receive from verified domains. By establishing a chain of trust, DKIM enhances overall email security and helps to maintain the integrity of communications.

In contrast, other options such as SMTP, IMAP, and POP3 serve different purposes. SMTP is primarily the transmission protocol used to send emails, not to verify sender authenticity. IMAP and POP3 are protocols used for retrieving emails from a server but do not provide mechanisms for verifying whether an email originated from a legitimate source. Therefore, they do not play a role in confirming the authenticity of email senders.